Final Exam deck!

Question 1

Aristotle

Answer 1

Viewed organisms as “fixed and unchanging”. Said that there are certain “affinities” among organisms, and concluded that organisms could be arranged on a ladder of complexity: “scala naturae”. This was contradictory to Darwin’s view

Question 1

Compare Darwin’s concept of descent with modification to the other prevailing ideas of his time

Answer 1

Darwin asserted that organisms are well-suited for life because of small changes that occur over large periods of time, instead of an intelligent Creator that finely-tuned organisms to be suited for their environment.

Question 2

Georges Cuvier

Answer 2

Paleontologist (studied fossils) - noted that the older the stratum, the more dissimilar the fossils were to current life-forms. Also noticed that some species appeared / disappeared. Even with these findings, he staunchly opposed the idea of evolution. Darwin used these findings to verify

Question 3

Jean-Baptiste de Lamark

Answer 3

Thought that use and disuse would dictate how parts would be genetically past down through generations - the more something was used, the stronger (and larger) it became, and vice versa. These characteristics were then genetically passed down. Although Darwin did not agree with use/disuse, he did agree with advantageous characteristics being passed down to offspring as acquired traits.

Question 4

Alfred Russel Wallace

Answer 4

Developed an hypothesis of natural selection that was nearly identical to Darwin’s. Darwin published his Origin of the Species book after reading Wallace’s hypothesis

Question 5

James Hutton

Answer 5

Earth’s geologic features can be explained by gradual mechanisms, like valleys being formed by rivers.

Question 6

Charles Lyell

Answer 6

Incorporated Hutton’s thinking into his proposal that the same geologic processes (gradual mechanisms) are operating today, at the same rate.

Question 7

How did Hutton and Lyell’s findings influence Darwin’s thoughts on descent with modification?

Answer 7

Their thinking confirmed that the world was much older than the projected ages that were widely circulated at the time. Therefore, if the world were older, it would allow for descent with modification

Question 8

Explain how, over time, natural selection results in organisms’ adaptation to their environment

Answer 8

In a genetically diverse population, traits that are more advantageous in some environments will be present (due to mutation, genetic drift, or gene flow). The challenges posed by a certain environment creates pressure (selective pressure) and these traits give their organisms advantage over other organisms with different traits, which means that the organisms with the more advantageous traits are more likely to survive and reproduce, passing along these advantageous traits to their offspring. Over time, this will result in the organism population adapting to its selective pressure via natural selection

Question 9

Use examples to show how evolution is supported by scientific evidence

Answer 9

Homologous structures: structures in different species that are similar because of common ancestry
Vestigial structures: A biological feature of an organism that is no longer functional and is a remnant of a structure that served a function in the organism’s ancestors
Biogeography: the distribution of species indicates the presence of a unifying Pangea state where all continents were connected and then broke off
Convergent evolution: evolution of similar features that are independent from evolutionary lineages. Analogous structures are structures that are similar as a result of convergent evolution (not to be mistaken for homologous structures)

Question 10

Describe factors that affect earth’s climate and explain how they influence patterns at different scales

Answer 10

Climate is affected by seasonality, large bodies of water, and mountains

Seasonality: variation in light and temperature with latitude, and how the sun hits the earth via the earth’s tilt

Bodies of Water affect climate: oceans (and their currents) along by nearby lakes moderate the climate of nearby land. Ocean currents flow between hot and cold depending on geolocation and have impacts on the land it passes

Mountains affect climate: rain shadow effect of sunlight and temperature wet - colder on the windward side, warmer, drier on the leeward side of the mountains

Question 11

If an ecologist were studying the regional interactions among multiple populations of different species and how they influence the exchange of materials between their various environments, then this would be an example of which kind of research?

Question 1 options:

population ecology

landscape ecology

ecosystem ecology

global ecology

Answer 11

landscape ecology

Question 12

What would happen to the seasons if Earth were tilted 35 degrees off its orbital plane instead of the usual 23.5 degrees?

Question 2 options:

The seasons would disappear.

The seasons would be shorter.

Winters and summers would be less severe.

Winters and summers would be more severe.

Answer 12

Winters and summers would be more severe.

Question 13

Which of the following might be an investigation of microclimate?

Question 3 options:

the effect of ambient temperature on the onset of caribou migration

the seasonal population fluctuation of nurse sharks in coral reef communities

competitive interactions among various species of songbirds during spring migration

how sunlight intensity affects plant community composition in the zone where a forest transitions into a meadow

Answer 13

how sunlight intensity affects plant community composition in the zone where a forest transitions into a meadow

Question 14

In creating global climate patterns, which of the following factors is the primary cause of all of the other factors that are listed?

Question 4 options:

global wind patterns

global ocean currents

precipitation differences between tropical and polar regions

variation in the heating of Earth’s surface

Answer 14

Variation in the heating of Earth’s surface

Question 15

For mountain ranges that are subjected to prevailing winds, why is the climate drier on the leeward (downwind) side?

Question 5 options:

The sun illuminates the leeward side of mountain ranges at a more direct angle, converting to heat energy, which evaporates most of the water present.

Air masses pushed by the prevailing winds are stopped by mountain ranges and the moisture is used up in the stagnant air masses on the leeward side.

Deserts create dry conditions on the leeward side of mountain ranges.

Pushed by the prevailing winds on the windward side, air is forced to rise, cool, condense, and drop its precipitation, leaving drier air to descend the leeward side.

Answer 15

Pushed by the prevailing winds on the windward side, air is forced to rise, cool, condense, and drop its precipitation, leaving drier air to descend the leeward side.

Question 16

Imagine some cosmic catastrophe jolts Earth so that its axis is perpendicular to the orbital plane between Earth and the sun. The most obvious effect of this change would be ________.

Question 6 options:

an increase in the length of a year

the elimination of tides

a decrease in temperature at the equator

the elimination of seasonal variation

Answer 16

the elimination of seasonal variation

Question 17

Flycatcher birds that migrate from Africa to Europe feed their chicks a diet that is almost exclusively moth caterpillars. The graph shows the peak dates of flycatcher arrival in Europe, bird hatching, and peak caterpillar season for the years 1980 and 2000. The y-axis is a measure of the abundance of birds, hatching chicks, and caterpillars.

The shift in the peak of caterpillar season is most likely due to ________.

Question 7 options:

acid precipitation in Europe

global warming

an innate change in the biological clock of the caterpillars

earlier migration returns of flycatchers

Answer 17

global warming

Question 18

The main cause of the increase in the amount of carbon dioxide in Earth’s atmosphere over the past 150 years is ________.

Question 8 options:

the burning of larger amounts of wood and fossil fuels

an increase in the amount of infrared radiation absorbed by the atmosphere

increased worldwide primary production

additional respiration by the rapidly growing human population

Answer 18

the burning of larger amounts of wood and fossil fuels

Question 19

Examine the figure, which notes the average barrels of oil used per person per year in different countries. What can be concluded?

Question 9 options:

Residents of more populated countries use more energy per person.

English-speaking countries tend to use more energy per person.

Residents in warmer climates use more energy per person.

Residents of more affluent, industrialized countries use more energy per person.

Answer 19

Residents of more affluent, industrialized countries use more energy per person.

Question 20

Describe Earth’s energy balance and how humans have altered it through the emission of greenhouse gases

Answer 20

Earth’s energy balance: 1) Solar Radiation passes through Earth’s atmosphere (some is reflected off the atmosphere) while most makes it through, 2) Radiation is absorbed on the Earth’s surface, warming it. 3) Energy is released as IR heat - some leaves the atmosphere while other parts get trapped in atmosphere via GHGs.

Humans have increased the levels of GHGs through carbon emissions, which leads to improper warming of the climate

Question 21

Explain how the distribution of species is limited by abiotic and biotic factors

Answer 21

Organisms have certain temperature/water/etc needs in order to survive (abiotic) and thus they are confined to areas that provide those things in the quantity that it needs.

Organisms can also be confined to certain areas because of predators, species that can outcompete them for resources, and harmful microorganisms (biotic) causing them to be limited by biotic factors

Question 22

Describe how ecological change and evolution affect one another over short and long periods

Answer 22

Example of long-term effects of ecological change and evolutionary change : origin and diversification of plants: the origin of plants themselves altered the chemical cycling of carbon leading to the removal of large quantities of CO2 in the atmosphere. As plant species continued to adaptively radiate over time, the appearance of new plant species allowed for new ecological niches, habitats, and sources of food for animals and insects, which stimulated speciation in animals too (as they adapted to fit these niches).

Example of short-term effect of ecological change on evolution: fisheries fishing for older cod will create selective pressure that favors younger cod that reproduce earlier. Younger cod do not reproduce at the same rate as older cod (slower) so the cod species may not be able to keep up with fish harvesting rates of the fishery

Question 23

Darwin and Wallace’s theory of evolution by natural selection was revolutionary because it ________.

Question 1 options:

proved that individuals acclimated to their environment over time

was the first theory to refute the ideas of special creation

dismissed the idea that species are constant and emphasized the importance of variation and change in populations

was the first time a biologist had proposed that species changed through time

Answer 23

dismissed the idea that species are constant and emphasized the importance of variation and change in populations

Question 24

The horizontal axis of the cladogram depicted below is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V-Z) represent various common ancestors. Let’s say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species.

In Darwin’s tree of life, each fork in the tree represents ________.

Question 2 options:

the most recent common ancestor of the subsequent branches

morphologic gaps in the fossil record

groups of living organisms

groups of extinct organisms

Answer 24

he most recent common ancestor of the subsequent branches

Question 25

Starting from the wild mustard Brassica oleracea, breeders have created the strains known as Brussels sprouts, broccoli, kale, and cabbage. Therefore, which of the following statements is correct?

Question 3 options:

Natural selection is rare in wild populations of wild mustard.

In this wild mustard, there is enough heritable variation to permit these different varieties.

Heritable variation is low in wild mustard—otherwise this wild strain would have different characteristics.

In wild mustard, most of the variation is due to differences in soil or other aspects of the environment.

Answer 25

In this wild mustard, there is enough heritable variation to permit these different varieties.

Question 26

Which of these conditions are always true of populations evolving due to natural selection?

Condition 1: The population must vary in traits that are heritable.

Condition 2: Some heritable traits must increase reproductive success.

Condition 3: Individuals pass on most traits that they acquire during their lifetime.

Question 4 options:

Condition 1 only

Condition 2 only

Conditions 1 and 2

Conditions 2 and 3

Answer 26

Conditions 1 and 2

Question 27

A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the triazine works well and almost all the pigweed dies; but after several years, the farmer sees more and more pigweed. Which of these statements explains why the pigweed reappeared?

Question 5 options:

Triazine-resistant weeds were more likely to survive and reproduce.

The herbicide company lost its triazine formula and started selling poor-quality triazine.

Natural selection caused the pigweed to mutate, creating a new triazine-resistant species.

Triazine-resistant pigweed has less-efficient photosynthesis metabolism.

Answer 27

Triazine-resistant weeds were more likely to survive and reproduce.

Question 28

Darwin used the phrase “descent with modification” to explain ________.

Question 6 options:

evolution of the unity and diversity of life

descent of all organisms from a single, ancient ancestor

unity of life

that habitat differences stimulate change in organisms

Answer 28

evolution of the unity and diversity of life

Question 29

Given a population that contains genetic variation, what is the correct sequence of the following events under the influence of natural selection?

1. Well-adapted individuals leave more offspring than do poorly adapted individuals.
2. A change occurs in the environment.
3. Genetic frequencies within the population change.
4. Poorly adapted individuals have decreased survivorship.

Question 7 options:

4 → 2 → 3 → 1

2 → 4 → 1 → 3

4 → 2 → 1 → 3

2 → 4 → 3 → 1

Answer 29

2 → 4 → 1 → 3

Question 30

Many crustaceans (for example, lobsters, shrimp, and crayfish) use their tails to swim, but crabs have reduced tails that curl under their shells and are not used in swimming. This is an example of ________.

Question 8 options:

a homologous structure

a vestigial trait

natural selection

convergent evolution

Answer 30

a vestigial trait

Question 31

If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, what would happen in environments that lack antibiotics?

Question 9 options:

These bacteria would try to make the cost worthwhile by locating and migrating to microenvironments where traces of antibiotics are present.

The number of genes conveying antibiotic resistance would increase in these bacteria.

These bacteria would be outcompeted and replaced by bacteria that have lost these genes.

These genes would be maintained in case the antibiotics appear.

Answer 31

These bacteria would be outcompeted and replaced by bacteria that have lost these genes.

Question 32

Who both taught Darwin the art of taxidermy and inspired him to travel on the HMS Beagle?

Question 10 options:

Charles Lyell

Georges Cuvier

Alfred Russel Wallace

John Edmonstone

Answer 32

John Edmonstone

Question 33

Define a population and three characteristics of populations: density, dispersion, and demographics

Answer 33

Population: is all the organisms of the same group/species that live ina specific area that can breed amongst themselves

Density: Number of individuals per unit area or volume
Dispersion: Pattern of spacing among individuals within the boundaries of the population
Demography: the study of key characteristics of populations and how they change over time

Question 34

Population ecology

Answer 34

Explores how biotic and abiotic factors influence the abundance, dispersion, and age structure of populations

Question 35

Identify what determines population growth

Answer 35

(Births - Deaths) + (Immigrants - Emigrants)

If both these numbers are positive, or if one number is much larger than the other negative number, populations will grow

Question 36

Mark recapture method

Answer 36

1) Capturing, tagging, and releasing a random sample of individuals (s) into a population 2)Mix back into the population 3) capture a 2nd sample of individuals (n) and note how many are marked (x)

Population size (N) is estimated by N= (sn)/(x)

Mark recapture method is used to estimate the size of the population

Question 37

Outline some major reasons to study population structure and growth

Answer 37

Understanding population structure and growth can help researchers come up with solutions with saving endangered populations. It can also help researchers understand how species interact with each other, and what the effect of climate change is on any given population.

Question 38

dN / dt = rN

Answer 38

Calculates the rate of change at each instant in time

can calculate how many individuals will be added to a population each year if r (per capita or per individual change in population size) is known and N (total population size) is known.

Question 39

Nt = N0 e^rt

Answer 39

The discreet equation that allows us to calculate how much a population has grown at any given time

Question 40

Life tables

Answer 40

Researchers follow the fate of a cohort, a group of individuals of the same age, from birth until all the individuals are dead.

Building a life table requires determining the proportion of the cohort that survives from one age group to the next

Calculating death rate: Nt-Nt+1 / Nt

Question 41

Differences between type 1, 2, and 3 survivorship curves

Answer 41

Type I: An organism that has low death rates at younger ages (starts flat)
Type III: An organism that has high death rates at younger ages (drops sharply at the start), but levels off as the survivors of the high-mortality juvenile stage live longer

Type II: Intermediate - constant death rate throughout the organism’s lifespan

Question 42

Identify characteristics of species with different survivorship curves

Answer 42

Type I: An organism that has low death rates at younger ages and through reproductive age is going to give lots of care to their offspring to make sure they survive

Type III: An organism with high death rates at younger ages will not provide the same care to offspring as seen in type I, hence the reason why a lot of the younger population dies off

Type II: intermediate curves suggest that the organism lives in an environment with a constant likelihood of death that doesn’t change

Question 43

Describe how life table data can be used to project future age structure, size, and growth rate of a population

Answer 43

It calculates the proportion of survivors and deaths per each year, which can help researchers visualize the growth of the population and the age structure (distribution of ages) of the organism.

Question 44

Describe the exponential model of population growth and its key assumptions

Answer 44

It’s key assumptions are that it assumes that the population is an idealized and unlimited environment

dN/dt = rN

Assuming that r= 1

This helps researchers understand the capacity of a species to increase and conditions that may facilitate this growth

Question 45

Discuss the distinction between factors that regulate population size and factors that determine population size

Answer 45

Only density-dependent factors can regulate population size, which involve: competition of resources, territoriality, disease, predation, intrinsic factors, and toxic wastes

Birth rate and/or death rate DO NOT change with population density - they are independent

Question 46

Contrast the logistic and exponential models of population growth and define population carrying capacity

Answer 46

Exponential growth models describe population growth in an idealized, unlimited environment, which helps us understand the ability of an organism population to grow in conditions that facilitate its growth

The logistic growth model measures the per capita rate of population growth and factors in carrying capacity

the carrying capacity (K) = is the size of the population where growth reaches 0

Question 47

Discuss how logistic regression incorporates limits to growth and shows how a population may stabilize around a maximum size (the carrying capacity)

Answer 47

The logistic model provides a useful starting point for thinking about how populations grow and for constructing more complex models. They are often measuring idealized environments that don’t have predators, food shortages, or other factors that may affect growth

The S-shape of the curve shows the area of highest growth (exponential growth, and the top portion of the S shows where population growth slows, when it approaches carrying capacity.

Question 48

Define life history and explain how life history traits are products of natural selection

Answer 48

Life history: traits that affect an organism’s schedule of reproduction and survival

Natural selection favors traits that improve an organism’s chances of survival and reproductive success.

Question 49

Contrast how density-dependent and density-independent affect population growth

Answer 49

Density dependent factors like competition, predation, disease, intrinsic factors, toxic waste, etc affect population growth quite obviously

Density independent factors are birth and death rates, that obviously also affect population growth but are not density dependent

Question 50

Explain why populations fluctuate in size using the hare and lynx example

Answer 50

Some populations undergo boom-bust cycles (in contrast to others that have more unpredictable intervals of population cycles)

Hare and lynx have population cycles that are roughly 10 years - since Lynx prey on hare, the lynx population is expected to cycle with hare population.

Why does the hare population cycle? Two main hypotheses: food shortages for hare, or other predators overexploiting prey.

Neither food supply nor predation alone explains hare cycles. Increasing food supply and removing predators improved hare density the most, but did not eliminate cycling (this was due to birds of prey not being able to be eliminated via fences)

Question 51

Discuss human population growth and projections of human population size in the future

Answer 51

The population is not growing exponentially anymore, but still increasing rapidly. No population can grow indefinitely, and this includes humans.

Demographic transition is associated with an increase in the quality of health care and improved access to education, especially for women

Question 52

Describe the process of a demographic transition and why it results in rapid population growth during the transition

Answer 52

4 stages

Stage 1: Food shortages, malnutrition, lack of sanitation and medicines, accidents, etc keep death rates high. Birth rates are high as well, so population stays relatively constant.

Stage 2: Economy development brings more jobs, better medical care, improved standard of living, etc. Death rate falls rapidly while birth rate stays relatively the same. Population increases.

Stage 3: Populations grow rapidly - death rates are low, birth rates remain high but tapering off

Stage 4: This is the conditions of developed countries - transition is complete. Birth and death rates are both low, population is stable

Question 53

Define ecological footprint and explain how it is determined

Answer 53

Ecological footprint: summarizes the aggregate land and water area needed to sustain a person, city, or nation

The use of logistic growth models can help determine the analysis of habitable land and food availability

Question 54

Discuss how carrying capacity relates to ecological footprint

Answer 54

The use of logistical growth models can help determine the necessary requirements for land and food availability, which directly will predict the carrying capacity of human beings and what population number the Earth can sustain realistically

Question 55

In the figure, which of the following survivorship curves implies that an animal may lay many eggs, of which a regular number die each year on a logarithmic scale?

Question 1 options:

curve C (type III)

curve B (Type II)

curves A or C

curve A (Type I)

Answer 55

curve B (Type II)

Question 56

To measure the population of lake trout in a 250-hectare lake, 400 individual trout were netted and marked with a fin clip, then returned to the lake. The next week, the lake was netted again, and out of the 200 lake trout that were caught, 50 had fin clips. Using the mark-recapture estimate, the lake trout population size could be closest to which of the following? (N = sn/x)

Question 2 options:

200

400

1,600

80,000

Answer 56

1,600

Question 57

An ecologist recorded 12 white-tailed deer, Odocoileus virginianus, per square kilometer (km2) in one woodlot and 20 km2 in another woodlot. What was the ecologist comparing?

Question 3 options:

carrying capacity

range

density

dispersion

Answer 57

density

Question 58

Uniform spacing patterns in plants such as the creosote bush are most often associated with ________.

Question 4 options:

patterns of high humidity

the concentration of nutrients within the population’s range

the random distribution of seeds

competitive interaction between individuals of the same population

Answer 58

competitive interaction between individuals of the same population

Question 59

A population of ground squirrels has an annual per capita birth rate of 0.06 and an annual per capita death rate of 0.02. Using these birth and death rates, calculate an estimate of the total number of individuals added to (or lost from) a population of 1,000 individuals in one year.

Question 5 options:

120 individuals added

40 individuals added

20 individuals added

400 individuals added

Answer 59

40 individuals added

Question 60

Starting from a single individual, what is the size of a population of bacteria at the end of a 2-hour time period if they reproduce by binary fission every 20 minutes? (Assume unlimited resources and no mortality.)

Question 6 options:

16

32

64

128

Answer 60

64

120 minutes / 20 = 6 times of binary fission

2^6 = 64

Question 61

During exponential growth, a population always ________.

Question 7 options:

grows at its maximum per capita rate

quickly reaches its carrying capacity

adds more new individuals when the population is small than when it is large

loses some individuals to emigration

Answer 61

grows at its maximum per capita rate

Question 62

According to the logistic growth equation, dN/dt = rN[(K-N)/K)], ________.

Question 9 options:

the population grows exponentially when K is small

population growth is zero when N equals K

the per capita growth rate (r) increases as N approaches K

the number of individuals added per unit time is greatest when N is close to zero

Answer 62

population growth is zero when N equals K

Question 63

Looking at the data in the figure from the hare/lynx experiment, what conclusion(s) can you draw?

I) Food is a factor in controlling hare population size.

II) Excluding lynx is a factor in controlling hare population size.

III) The effect of excluding predators and adding food in the same experiment is greater than the sum of excluding lynx alone plus adding food alone.

Question 10 options:

only III

I, II, and III

only II

only I

Answer 63

I, II, and III

Question 64

Each female of a particular fish species produces millions of eggs per year. Draw and label the most likely survivorship curve for this species, and explain your choice.

Answer 64

Type III is most likely, because the female cannot cater to each offspring realistically and thus many will die

Question 65

Imagine that you are constructing a life table like Table 53.1 for a different population of Belding’s ground squirrels. If 485 individuals are alive at the start of year 0-1 and 218 are still alive at the start of year 1-2, what is the proportion alive at the start of each of these years?

Answer 65

The proportion alive at the start of 0-1 is (1.000), all are alive

The proportion alive at the start of 1-2 would be 218/485 = .449

Question 66

A male stickleback fish attacks other males that invade its nesting territory. Predict the likely pattern of dispersion for male sticklebacks, and explain your reasoning.

Answer 66

Male sticklebacks would likely have a uniform pattern of dispersion, with antagonistic interactions maintaining a relatively constant spacing between them

Question 67

Clumped dispersion pattern cause

Answer 67

Organisms grouping together where food is abundant

Question 68

Uniform dispersion pattern cause

Answer 68

Maintained by aggressive interactions between neighbors of the population

Question 69

Random spacing pattern

Answer 69

Seeds scattered in random patterns via wind or animals

Question 70

Explain why a population that fits the logistic growth model increase more rapidly at intermediate size than at relatively small and large sizes.

Answer 70

When N is small, there are not many organisms to participate in reproduction = low rate. When N is high, near carrying capacity, growth rate will slow due to lack of resources. Therefore, intermediate growth is best suited.

Question 71

Given the latitudinal sunlight intensity, how might you expect the carrying capacity of plant species found at the equator compare with that of plant species found at high latitudes?

Answer 71

It would be expected that plants near the equator will have a larger carrying capacity than at high latitudes because more sunlight is at the equator.

Question 72

Suppose that a sudden change in environmental conditions caused a substantial drop in a population’s carrying capacity. Predict how natural selection and genetic drift might affect this population.

Answer 72

Sudden change will cause a shift in allele frequencies in a population, and natural selection will favor individuals with advantageous genes, which will reduce genetic diversity. Lower carrying capacity will also cause population to drop, and thus will cause harmful alleles to be more prevalent due to genetic drift and therefore reducing the likelihood of the population to rebound.

Question 73

Negative feedback is a process that regulates biological systems. Explain how the density-dependent birth rate of dune fescue grass exemplifies negative feedback

Answer 73

Negative feedback results in decrease of birthrate due to the output.

Dune fescue grass reproduce to high quantities (leading to higher population density), which this output will have a negative effect on birthrate

Question 74

How does a human population’s age structure affect its growth rate?

Answer 74

Bottom-heavy (disproportionately young): will cause growth rate to increase

Uniform age structure: growth rate is stable

Top-heavy (disproportionately old): growth rate will decrease

Question 75

How have the rate and number of people added to the human population each year changed in recent decades?

Answer 75

The growth rate of humans has slowed, but the population is still increasing rapidly due to an already large population

Question 76

As an ecologist who manages a wildlife preserve, you want to increase the preserve’s carrying capacity for a particular endangered species. How might you go about accomplishing this?

Answer 76

Increasing food supply, limiting predators, and providing more sites for nesting and reproduction

Question 77

Explain why ecological trade-offs are common.

Answer 77

They are common because organisms don’t have unlimited food/resources. Therefore, use of energy for one function (like reproduction) has a trade-off where there is less energy for other functions (like growth and reproduction).

Question 78

Give an example of on biotic and one abiotic factor that contribute to yearly fluctuations in the size of the human population.

Answer 78

Biotic: disease, pathogen
Abiotic: natural disasters like earthquakes, tornados, hurricanes, etc

Question 79

How do humans differ from other species in the ability to “choose” a carrying capacity for their environment?

Answer 79

Humans are equipped with higher levels of thinking and can control birthrates via means of contraception, and also controlling what we eat / personal lifestyle, which then has a direct effect on the carrying capacity of Earth

Question 80

Describe how genetic variation arises and why it is a prerequisite for evolution

Question 81

Use allele-frequency data to predict the genotype frequencies of a population in Hardy-Weinberg equilibrium

Answer 81

go for it

Question 82

Differentiate between how natural selection, genetic drift, and gene flow affect allele frequencies in a population

Answer 82

Natural selection promotes individuals with certain heritable traits that provide an advantage to a particular environment. Therefore, natural selection affects gene frequencies as it favors desirable genes in a population

Genetic drift, on the other hand, revolves around chance events that occur and will result in allele frequency changes

Gene flow affects the frequencies of alleles in a population based on the movement of fertile individuals and their gametes. They physically transport varying genetic information to new areas and mate/produce offspring thus affecting allele frequencies.

Question 83

Explain the process of natural selection

Answer 83

Genetic varations in a population lead to advantageous and disadvantageous traits in a certain environment with a certain selective pressure. Beings with more advantageous traits will be favored in this environment, which means they will be more likely to reproduce, passing their advantageous traits to their offspring.

Question 84

Neutral variation

Answer 84

Mutations in noncoding regions of DNA (introns) that result in traits that are neither disadvantageous or advantageous in the environment. This can also be caused by redundant exons in genetic code that aren’t expressed.

Question 85

Genetic variation

Answer 85

Genetic differences among individuals in a population, this is required for natural selection

Question 86

Genetic drift

Answer 86

Revolves around chance events that decrease genetic variability in a population (more than likely a result from a large disaster)

Question 87

Gene flow

Answer 87

Affects gene frequencies in a population due to migration of new genetic traits from neighboring populations

Question 88

Bottleneck effect

Answer 88

A dramatic change in population due to a disaster which diminishes genetic variation. This process could randomly select alleles that may be advantageous or disadvantageous. Since genetic variability has decreased, the surviving members mating with each other will produce less genetically varying offspring, and populations may take a long time to recover (even longer if the surviving traits are not advantageous).

Question 89

Founder effect

Answer 89

When a few individuals from a population are isolated and establish a new population with a differing gene pool from the source population

Question 90

Directional selection

Answer 90

Shifts overall genetic makeup to one extreme of the distribution

Question 91

Disruptive selection

Answer 91

Favors variants at either extreme of the distribution, with a dip in the intermediate portion of the distribution

Question 92

Stabilizing selection

Answer 92

Favors intermediate genetic variants while eliminating either extreme

Question 93

Balancing selection

Answer 93

Advantage of a trait is determined by how common it is in the population (oscillating defenses of the right or left mouthed fish)

Heterozygote advantage is also an example of balancing selection

Question 94

Heterozygote advantage

Answer 94

Natural selection favoring two or more alleles at a locus due to heterozygotes having an advantage over the extremes - sickle cell anemia example

Another example of balancing selection

Question 95

Relative fitness

Answer 95

The contribution an individual makes to the gene pool of the next generation relative to the contributions of other individuals

Question 96

Microevolutions occur when ________.

Question 1 options:

individuals within all species vary in their phenotypic traits

a bird has a beak of a particular size that does not grow larger during a drought

changes in allele frequencies in a population occur over generations

gene flow evenly transfers alleles between populations

Answer 96

changes in allele frequencies in a population occur over generations

Question 97

Which statement about the beak size of finches on the island of Daphne Major during prolonged drought is true?

Question 2 options:

Each bird that survived the drought produced only offspring with deeper, stronger beaks than seen in the previous generation.

Each bird evolved a deeper, stronger beak as the drought persisted.

Each bird’s survival was strongly influenced by the depth and strength of its beak as the drought persisted.

The frequency of the strong-beak alleles increased in each bird as the drought persisted.

Answer 97

Each bird’s survival was strongly influenced by the depth and strength of its beak as the drought persisted.

Question 98

Which statement about variation is true?

Question 3 options:

All nucleotide variability results in neutral variation.

All new alleles are the result of nucleotide variability.

All phenotypic variation is the result of genotypic variation.

All genetic variation produces phenotypic variation.

Answer 98

All new alleles are the result of nucleotide variability.

Question 99

Homozygotes with two sickle-cell alleles are selected against because of mortality. However, heterozygotes for sickle-cell allele experience little effects of sickle allele and are more likely to survive malaria. The net effect of this exposure produced evolutionary change in areas where malaria is endemic by ________.

Question 4 options:

increasing the number of infected mosquitoes

increasing sickle-cell allele frequency

causing sickle-cell allele

distortion of red blood cells

Answer 99

increasing sickle-cell allele frequency

Question 100

Cystic fibrosis is a genetic disorder in homozygous recessives that causes death during the teenage years. If 9 in 10,000 newborn babies have the disease, what are the expected frequencies of the dominant (A1) and recessive (A2) alleles according to the Hardy-Weinberg equation?

Question 5 options:

f(A1) = 0.9997, f(A2) = 0.0003

f(A1) = 0.9604, f(A2) = 0.0392

f(A1) = 0.9700, f(A2) = 0.0300

f(A1) = 0.9800, f(A2) = 0.0200

Answer 100

f(A1) = 0.9700, f(A2) = 0.03

Question 101

Suppose 64% of a remote mountain village can taste phenylthiocarbamide (PTC) and must, therefore, have at least one copy of the dominant PTC taster allele. If this population conforms to Hardy-Weinberg equilibrium for this gene, what percentage of the population must be heterozygous for this trait?

Question 6 options:

32%

16%

40%

48%

Answer 101

48%

Question 102

Researchers studying a small milkweed population note that some plants produce a toxin and other plants do not. They identify the gene responsible for toxin production. The dominant allele (T) codes for an enzyme that makes the toxin, and the recessive allele (t) codes for a nonfunctional enzyme that cannot produce the toxin. Heterozygotes produce an intermediate amount of toxin. The genotypes of all individuals in the population are determined (see chart) and used to determine the actual allele frequencies in the population.

Is this population in Hardy-Weinberg equilibrium?

Question 7 options:

Yes.

More information is needed to answer this question.

No; there are more heterozygotes than expected.

No; there are more homozygotes than expected.

Answer 102

No; there are more homozygotes than expected.

Question 103

An earthquake decimates a ground-squirrel population, killing 98% of the squirrels. The surviving population happens to have broader stripes, on average, than the initial population. If broadness of stripes is genetically determined, what effect has the ground-squirrel population experienced during the earthquake?

Question 8 options:

a genetic bottleneck

directional selection

disruptive selection

a founder event

Answer 103

a genetic bottleneck

Question 104

Over time, the movement of people on Earth has steadily increased. This has altered the course of human evolution by increasing ________.

Question 9 options:

gene flow

nonrandom mating

geographic isolation

genetic drift

Answer 104

gene flow

Question 105

A population of lab flies (drosophila melanogaster) are given endless resources (space and food) to live and reproduce. A mutation arises in that population that very slightly beneficial. This allele is most likely to be

Question 10 options:

equally likely to be fixed or lost

need more information

fixed

lost

Answer 105

fixed

Question 106

Biological species concept

Answer 106

Biological species concept: a group of populations whose members have the potential to interbreed in nature and produce viable fertile offspring

Question 107

Allopatric speciation

Answer 107

The physical separation of two populations –> interruption of gene flow

Question 108

Sympatric speciation

Answer 108

No physical barrier (like geographic barrier) that inhibits gene flow. Reproduction is prevented by sexual selection, polyploidy, and habitat differentiation

Question 109

Polyploidy

Answer 109

The presence of extra sets of chromosomes - will cause a new biological species in sympathy within a single generation

Question 110

Hybrid zones / possible outcomes over time

Answer 110

Hybrid zones are areas of interbreeding between two populations, and involve 3 possible outcomes:

Individuals can hybridize readily –> No speciation

Individuals do not hybridize at all –> full speciation

Individuals can hybridize but offspring have reduced fitness –> speciation in progress. Selection for evolution of strong reproductive barriers.

Question 111

Prezygotic barriers

Answer 111

Barriers that prevent mating and/or fertilization

Habitat isolation: Two species that occupy different habitats within the same area may encounter each other rarely, if at all

Temporal isolation: Species that breed during different times of the day, different seasons, or different years cannot mix gametes

Behavioral isolation: courtship rituals that attract mates are unique to a species but not others serve as barriers

Mechanical isolation: mating is attempted , but morphological differences prevent its successful completion

Gametic isolation: mating is attempted, but the sperm of one species may not be able to fertilize the eggs of another species

Question 112

Postzygotic barriers

Answer 112

Barriers that prevent zygote development or reproduction

Reduced hybrid viability, fertility, and hybrid breakdown, causing lack of reproduction among hybrids

Question 113

Two populations of birds with somewhat different coloration live on opposite sides of a peninsula. The habitat between the populations is not suitable for these birds. When birds from the two populations are brought together, they produce young whose appearance is intermediate between the two parents. These offspring will breed with each other or with birds from either parent population, and all offspring of these pairings appear intermediate to various degrees.

What keeps the two populations separate?

Question 1 options:

lack of hybrid viability

habitat isolation

temporal reproductive isolation

behavior isolates reproductive activities

Answer 113

habitat isolation

Question 114

If biological species are defined in terms of reproductive compatibility, the formation of a new species hinges on ________.

Question 2 options:

reproductive isolation

gene pool expansion

hybrid formation

gene flow

Answer 114

reproductive isolation

Question 115

Three populations of crickets look very similar, but the males have courtship songs that sound different. What function would this difference in song likely serve if the populations came in contact?

Question 3 options:

a behavioral reproductive isolating mechanism

a temporal reproductive isolating mechanism

a postzygotic isolating mechanism

a gametic reproductive isolating mechanism

Answer 115

a behavioral reproductive isolating mechanism

Question 116

Which statement describes unity within a species?

Question 4 options:

A species is described in terms of its interaction with living and non-living environment.

The DNA sequence lacks similarities.

Members have the potential to interbreed in nature and produce viable, fertile offspring.

A species can be distinguished by body shape and other structural features.

Answer 116

Members have the potential to interbreed in nature and produce viable, fertile offspring.

Question 117

Macroevolution is ________.

Question 5 options:

defined as a change in allele or gene frequency over the course of many generations

defined as the evolution of microscopic organisms into organisms that can be seen with the naked eye

evolution above the species level

the same as microevolution, but includes the origin of new species

Answer 117

evolution above the species level

Question 118

Which of the various species concepts distinguishes two species based on the degree of genetic exchange between their gene pools?

Question 6 options:

morphological

biological

genetic

ecological

Answer 118

biological

Question 119

Two species of frogs belonging to the same genus occasionally mate, but the embryos stop developing after a day and then die. These two frog species separate by ________.

Question 7 options:

reduced hybrid viability

gametic isolation

reduced hybrid fertility

hybrid breakdown

Answer 119

reduced hybrid viability

Question 120

Which of the following describes the most likely order of events in allopatric speciation?

Question 8 options:

genetic isolation, genetic drift, divergence

genetic drift, genetic isolation, divergence

divergence, genetic drift, genetic isolation

genetic isolation, divergence, genetic drift

Answer 120

genetic isolation, genetic drift, divergence

Question 121

You want to study divergence of populations, and you need to maximize the rate of divergence to see results within the period of your grant funding. You will form a new population by taking some individuals from a source population and isolating them so the two populations cannot interbreed. What combination of characteristics would maximize your chance of seeing divergence in this study?

1. Choose a random sample of individuals to form the new population.
2. Choose individuals from one extreme to form the new population.
3. Choose a species to study that produces many offspring.
4. Choose a species to study that produces a few, large offspring.
5. Place the new population in the same type of environment as the source population.
6. Place the new population in a novel environment compared to that of the source population.

Question 9 options:

1, 3, and 6

1, 4, and 6

2, 3, and 5

2, 3, and 6

Answer 121

2, 3, and 6

Question 122

Which information is relevant to the ecological species definition?

Question 10 options:

Hawthorn and apple maggot flies are genetically distinguishable and have a distinct genetic profiles.

Hawthorn and apple maggot flies strongly prefer to mate and lay fertilized eggs in hawthorns and apples, respectively.

There is a 4-6% hybridization rate between hawthorn and apple maggot flies.

Hawthorn and apple maggot flies are physically indistinguishable.

Answer 122

Hawthorn and apple maggot flies strongly prefer to mate and lay fertilized eggs in hawthorns and apples, respectively.

Question 123

Describe the steps by which simple cells may have originated from non-living materials

Answer 123

1. Abiotic synthesis of small organic molecules
2. Joining of these molecules into macromolecules
3. Packaging of molecules into protocells
4. Origin of self-replicating molecules

Question 124

Explain what fossils are, how they are dated, and what the fossil record can reveal about life’s history

Answer 124

Fossils are remnants of organisms that have been preserved

Fossil record shows macroevolutionary changes over large time scales: emergence of terrestrial vertebrates, impact of mass extinction, origin of key adaptations

Fossil record is dated by using radiometric dating, using half lives

Question 125

Describe how changes in the sequence or regulation of genes can result in major changes in body form

Answer 125

Hox genes can dictate major morphological changes to body form via small base pair changes to their genome.

Question 126

Use examples to show how novel and complex structures can arise with descent with modification

Answer 126

The complex structure of the eye is a result of many years of small modifications via natural selection, each stage giving more function to the eye than the last.

Evidence for this is shown in organisms that have intermediate or primitive structures that resemble the eye, with limited function

Question 127

Microevolution

Answer 127

The change of allele frequency within a population

Question 128

Macroevolution

Answer 128

Broad patterns of evolutionary change above species level

Question 129

Speciation

Answer 129

The divergence of a new species, which forms a bridge between micro and macroevolution

Question 130

Ribozyme

Answer 130

Enzyme of RNA that catalyzes a chemical reactions, making complementary copies of short stretches of RNA

This characteristic RNA (along with genetic information storage) leads researchers to believe that RNA was the first genetic material, given its information storage and catalytic properties

Question 131

Protocell

Answer 131

An abiotic precursor that resembled a cell because of its membrane-like structure, filled with fluid, and kept an environment inside it that was different from its surroundings

Similar to living cells

Question 132

Endosymbiont theory

Answer 132

Theory about the origin of Eukaryotic cells, were an ancestral prokaryote engulfed an aerobic bacterium and they lived symbiotically until the bacterium became a part of the cell, forming mitochondrial organelles

A second endosymbiotic system occurs when an ancestral eukaryotic cell (a heterotroph) engulfed a photosynthetic bacterium, and this produced plastid organelles

Question 133

Adaptive radiation

Answer 133

Follow mass extinctions, evolution of novel characteristics, or colonization of new regions.

Periods of rapid change and speciation: a rapid increase in the number of species with a common ancestor, characterized by great ecological and morphological diversity.

Question 134

Evo devo

Answer 134

Field of biological research that compares the developmental processes of different organisms to infer how developmental processes evolved

Question 135

Developmental genes and their role

Answer 135

They dictate development control rate, timing and spatial pattern of changes in an organism’s form as it develops to adulthood

Question 136

Heterochrony

Answer 136

Evolutionary change in the rate and timing of developmental events. Altering timing of reproductive development relative to the development of non-reproductive organs

This has an impact on body shape (human vs chimp skull)

Question 137

Paedomorphosis

Answer 137

The rate of reproductive development accelerates compared with somatic development (which is slower) this results in sexually mature species with juvenile morphology

Question 138

Homeotic genes

Answer 138

Genetic material that determines where body features go

Question 139

Hox genes

Answer 139

Are a class of homeotic genes that provide positional information during animal embryonic development

Changes in developmental genes can result in new morphological forms

Question 140

Changes in Gene Regulation

Answer 140

Dictates which genes are regulated, and are probably the more likely contributor to changes to organism forms than sequence changes

Ex: sticklebacks in lakes have fewer spines than marine relatives due to lack of predation (Pitx1 controls ventral spine formation)

Question 141

Changes in gene sequence

Answer 141

Changes in a gene sequence that cause major changes to morphological form, as in changes to homeotic genes

Question 142

Which of the following is the correct sequence of events in the origin of life?

I. Formation of protocells

II. Synthesis of organic monomers

III. Synthesis of organic polymers

IV. Formation of DNA-based genetic systems

Question 1 options:

I, II, III, IV

I, III, II, IV

II, III, I, IV

II, III, IV, I

Answer 142

II, III, I, IV

Question 143

The first genetic material on Earth was probably ________.

Question 2 options:

DNA produced by reverse transcriptase from abiotically produced RNA

DNA molecules whose information was transcribed to RNA and later translated in polypeptides

self-replicating RNA molecules

oligopeptides located within protocells

Answer 143

self-replicating RNA molecules

Question 144

Which of the following organisms would be most likely to form a fossil?

Question 3 options:

a common worm

a rare squirrel

a rare worm

a common squirrel

Answer 144

a common squirrel

Question 145

You are the lucky student of a wacky professor who develops a time machine. He asks if you will test it with him. You get in, and there is an immediate glitch—the date readout fails so that when you land, you are not sure what era you are in. As your time machine lands, you see an unusual landscape before you. As you open the door, you realize you cannot breathe. You quickly shut the door, realizing you are in the ________.

Question 4 options:

Cambrian period

Mesozoic era

Archaean eon

Cenozoic era

Answer 145

Archaean eon

Question 146

What is true of the Cambrian explosion?

Question 5 options:

The Cambrian explosion marks the appearance of filter-feeding animals in the fossil record.

There are fossils of animals in geological strata that are older than the Cambrian explosion.

Only the fossils of microorganisms are found in geological strata older than the Cambrian explosion.

The Cambrian explosion is evidence for the instantaneous creation of life on Earth.

Answer 146

There are fossils of animals in geological strata that are older than the Cambrian explosion.

Question 147

Which factor most likely caused animals and plants in India to differ greatly from species in nearby southeast Asia?

Question 6 options:

India is in the process of separating from the rest of Asia.

The climates of the two regions are similar.

India was a separate continent until 45 million years ago.

Life in India was wiped out by ancient volcanic eruptions.

Answer 147

India was a separate continent until 45 million years ago.

Question 148

What concept explains the evolution of complex eyes?

Question 7 options:

Complex eyes evolved through a series of steps that benefited the eyes.

Mollusc eye’s evolution was dependent on vertebrate eye evolution.

Mollusc eyes evolved from a different ancestor than vertebrate eyes.

Through evolutionary history, eyes lose function of vision.

Answer 148

Complex eyes evolved through a series of steps that benefited the eyes.

Question 149

Bagworm moth caterpillars feed on evergreens and carry a silken case or bag around with them in which they eventually pupate. Adult female bagworm moths are larval in appearance; they lack the wings and other structures of the adult male and instead retain the appearance of a caterpillar even though they are sexually mature and can lay eggs within the bag. This is a good example of ________.

Question 8 options:

allometric growth

paedomorphosis

sympatric speciation

adaptive radiation

Answer 149

paedomorphosis

Question 150

The loss of ventral spines by modern freshwater sticklebacks is due to natural selection operating on the phenotypic effects of Pitx1 gene ________.

Question 9 options:

duplication (gain in number)

elimination (loss)

silencing (loss of expression)

mutation (change)

Answer 150

silencing (loss of expression)

Question 151

The duplication of homeotic (Hox) genes has been significant in the evolution of animals because it ________.

Question 10 options:

permitted the evolution of novel forms

caused the extinction of major groups

reduced morphological diversity into simpler forms of life

allowed animals to survive on significantly fewer calories

Answer 151

permitted the evolution of novel forms

Question 152

Explain how phylogenies are used

Answer 152

Used to classify organisms and determine their evolutionary relationships (systematics)

Question 153

Derived vs. Ancestral traits, and explain how they are used to construct phylogenetic trees

Answer 153

Ancestral character: originated in an ancestor of a taxon

Derived character: evolutionary novelty unique to a particular clade

Understanding when derived characters appeared is useful

Question 154

Cladistics

Answer 154

The process of grouping organisms by ancestry

Question 155

Clade

Answer 155

A group of species that includes an ancestor and all its descendants

Question 156

Outgroup

Answer 156

a species or group that is closely related to ingroup, but has diverged before the rest of the ingroup

Question 157

Ingroup

Answer 157

various species that are being studied in phylogenetic tree that is being built

Question 158

Construct a phylogenetic tree from a character table and discuss evolutionary relationships among organisms

Answer 158

Already practiced this, but re-visit if you have time!

Question 159

Explain what molecular clocks are and how they are used using the HIV example

Answer 159

Molecular clocks are - constant rates of evolution found in some genes, and since they are used to predict evolutionary age/time by assuming constant evolutionary rate, has been used to track the lineage of the HIV virus

Question 160

Hierarchical classification

Answer 160

Kingdom - phylum - class - order- family - genus-species

Question 161

Sister taxa

Answer 161

Pairs of terminal taxa and/or clades that branch from a common node (ancestor) indicate that they are closely evolutionarily related.

Question 162

Polytomy

Answer 162

A node where more than two lineages descend from a common node (ancestor) usually means that more research needs to be done to determine similarity

Question 163

Homoplasy

Answer 163

Coincidental matches in nucleotide sequences in otherwise very different genetic codes

Question 164

Monophyletic

Answer 164

A group of evolutionarily related taxa with all of their ancestors

Question 165

Paraphylatic

Answer 165

Include some, but not all descendants of a common ancestor

Question 166

Polyphyletic

Answer 166

Made up of a group of taxa that have converged via a similar trait/characteristic but do not share a recent common ancestor

Question 167

Maximum parsimony

Answer 167

A phylogenetic tree that requires the fewest evolutionary events (appearances of shared derived characters) is most likely

Question 168

Homologous genes

Answer 168

Homologous genes found in multiple species due to speciation

Nucleotide substitutions are proportional to time since divergence

Question 169

Orthologous genes

Answer 169

Homologous genes found in genomes of related species from a common ancestor

Nucleotide substitutions are proportional to time since divergence

Question 170

If organisms A, B, and C belong to the same class but to different orders and if organisms C, D, and E belong to the same order but to different families, which of the following pairs of organisms would be expected to show the greatest degree of structural homology?

Question 3 options:

A and D

B and D

B and C

D and E

Answer 170

D and E

Question 171

Your professor wants you to construct a phylogenetic tree of orchids. They give you tissue from seven orchid species and one lily. What is the most likely reason they gave you the lily?

Question 6 options:

to serve as an outgroup

to see if the lily and the orchids show all the same shared derived characters

to demonstrate likely homoplasies

to see if the lily is a cryptic orchid species

Answer 171

to serve as an outgroup

Question 172

The lakes of northern Minnesota are home to many similar species of damselflies of the genus Enallagma. These species have apparently undergone speciation from ancestral stock since the last glacial retreat about 10 thousand years ago. Sequencing which of the following would probably be most useful in sorting out evolutionary relationships among these closely related species?

Question 10 options:

conserved regions of nuclear DNA

amino acids in proteins

ribosomal RNA

mitochondrial DNA

Answer 172

mitochondrial DNA

Question 173

Direct transfer vs vector-borne diseases vs zoonotic diseases

Answer 173

Direct transfer: Disease is transmitted between organisms directly through some form of bodily contact

Zoonotic diseases: Originate as an animal disease and can spread to humans

Vector-borne diseases: Animal vector transmits disease from one host to another (ie tick bite)

Question 174

What are the factors that impact the spread of disease?

Answer 174

Water, sanitation, food and air quality

Question 175

Define S, I, SI, Beta, Beta * S * I, L, and m

Answer 175

S: number of susceptible individuals
I: Number of infected individuals
SI: Probability of infected individuals encountering susceptible individuals
Beta: Transmission coefficient (how effectively disease spreads)

BetaSI = disease transmission
L = infectious period
m= per infection recovery rate (and death rate)

Question 176

What are the assumptions of the SIR model?

Answer 176

Once an individual is infected they become immediately infectious

Once an individual has recovered they are never again susceptible to the disease

Population is perfectly mixed

Question 177

Herd Immunity

Answer 177

When a population is “immune” to a disease due to sufficient vaccination/natural immunity

Question 178

How can diseases be controlled?

Answer 178

Quarantine (isolation)

Sanitation

Behavior (masks, distancing)

Immunization

Reduce transmission rates, and infectious period, and reduce population densities.

Question 179

Structure and functional adaptations of prokaryotes

Answer 179

Unicellular, have a variety of shapes but usually either cocci, bacilli or spiral , they lack a nuclear membrane, they have cell walls (protect cell, prevents bursting from hypotonic environment) made of peptidolycan.

Question 180

What are the two types of bacteria cell wall compositions?

Answer 180

Gram-positive (simpler walls with a large amount of peptidoglycan), and gram-negative (less peptidoglycan, has outer membrane)

Question 181

Why are antibiotics more effective against gram-positive bacteria?

Answer 181

They target peptidoglycan, which gram-positive cells have more of than gram-negative, making them more susceptible to antibiotics

Question 182

Capsule

Answer 182

A polysaccharide or protein layer that is on the outermost part of a bacterial cell, allows it to stick to surfaces and is often the catalyst for diseases

Question 183

Endospores

Answer 183

Formed by prokaryotes - metabolically inactive cells that can withstand harsh conditions for centuries

Question 184

Nucleoid

Answer 184

A circular chromosome in prokaryotes

Prokaryotes have less DNA than eukaryotes

Question 185

Plasmid

Answer 185

Independently replicating DNA molecules, usually only carrying a few genes (often for antibiotic resistance)

Question 186

Why are prokaryotes so genetically diverse?

Answer 186

Due to rapid reproduction, mutation (although low, the rapid reproduction makes each mutation much more impactful), and genetic recombination

Question 187

Transduction

Answer 187

A type of genetic recombination where bacteriophages (a virus that infects bacteria) take genetic information from one bacterium to another unrelated bacterium

Question 188

Conjugation

Answer 188

A type of genetic recombination where two prokaryotes (usually from the same species) exchange genetic material one way through an elongated structure called a pilus (F factor DNA is needed for the production of a pili)

Question 189

Transformation

Answer 189

A type of genetic recombination where a prokaryotic cell engulfs a free-floating piece of genetic material and incorporates it into its own genome

Question 190

R plasmids

Answer 190

Specifically, carry genes for antibiotic resistance. Many also code for pili to aid in conjugated genetic recombination.

Question 191

Horizontal gene transfer

Answer 191

The sharing of genetic information between two organisms (or cells) that are not related via parent-offspring relationship.

Question 192

Photoautotroph

Answer 192

Organisms that rely on light for energy but need CO2 to derive a carbon source

Question 193

Chemoautotroph

Answer 193

Organisms that rely on inorganic chemicals for energy, need CO2 to derive a carbon source

Question 194

Photoheterotroph

Answer 194

Organisms that rely on light for energy, and organic compounds as a carbon source

Question 195

Chemoheterotroph

Answer 195

Organisms rely on organic compounds for both energy and carbon sources

Question 196

Extremophiles (different types)

Answer 196

Archaea that live in extreme environments

Extreme halophiles: highly saline environments

Extreme thermophiles: thrive in hot environments

Question 197

In what ways are prokaryotes important to the biosphere?

Answer 197

They’re symbionts: forming supportive connections with a larger hosts (also can be commensalist- neutral, or parasite - negative)

They also can help break down organic materials in soil

Question 198

Use the information in the following paragraph to answer the question.

A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. It adheres to the intestinal lining using a feature that also protects it from phagocytes, bacteriophages, and dehydration. Fecal matter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with water and boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively little peptidoglycan.

This bacterium’s ability to survive in a human who is taking penicillin pills may be due to the presence of ________.

Question 1 options:

lipopolysaccharides in the cytoplasm

long polypeptides in the cell wall

peptidoglycan in the cell wall

gram-negative cell wall

Answer 198

gram-negative cell wall

Question 199

In a bacterium that possesses antibiotic resistance and the potential to persist through very adverse conditions, such as freezing, drying, or high temperatures, DNA should be located within, or be part of, which structures?

Question 2 options:

nucleoid, fimbriae, and plasmids

plasmids, nucleoid, and endospore

fimbriae, nucleoid, and endospore

endospore, fimbriae, and plasmids

Answer 199

plasmids, nucleoid, and endospore

Question 200

If a bacterium regenerates from an endospore that did not possess any of the plasmids that were contained in its original parent cell, the regenerated bacterium will probably also lack ________.

Question 3 options:

water in its cytoplasm

a chromosome

antibiotic-resistant genes

a cell wall

Answer 200

antibiotic-resistant genes

Question 201

Termites eat wood, but many do not produce enzymes themselves that will digest the cellulose in the wood. Instead, some termites house a complex community of protozoa, bacteria, and archaea that could help digest the cellulose. Imagine an experiment that fed termites either wood only or wood and antibiotics, and then measured the amount of energy extracted from the wood. If both groups gained equal amounts of energy, which of the conclusions is the most logical?

Question 4 options:

We would conclude that the protozoa contributed to digestion of cellulose and lignin.

We would conclude that the bacteria did not contribute to digestion of cellulose and lignin.

We would conclude that none of the three groups were needed to digest cellulose and lignin.

We would conclude that the archaea contributed to digestion of cellulose and lignin.

Answer 201

We would conclude that the bacteria did not contribute to digestion of cellulose and lignin.

Question 202

The following question refers to the figure.

In this eight-year experiment, 12 populations of E. coli, each begun from a single cell, were grown in low-glucose conditions for 20,000 generations. Each culture was introduced to fresh growth medium every 24 hours. Occasionally, samples were removed from the populations, and their fitness in low-glucose conditions was tested against that of members sampled from the ancestral (common ancestor) E. coli population. (fitness gradually increases over generations)

The cells in the 12 cell lines grown in low-glucose conditions showed the effects of which of the following processes?

Question 5 options:

gene flow and genetic drift

conjugation and transformation

natural selection and mutation

natural selection and gene flow

Answer 202

natural selection and mutation

Question 203

In a hypothetical situation, the genes for sex pilus construction and for tetracycline resistance are located on the same plasmid within a particular bacterium. If this bacterium readily performs conjugation involving a copy of this plasmid, then the result should be the ________.

Question 6 options:

subsequent loss of tetracycline resistance from this bacterium

production of endospores among the bacterium’s progeny

temporary possession by this bacterium of a completely diploid genome

rapid spread of tetracycline resistance to other bacteria in that habitat

Answer 203

rapid spread of tetracycline resistance to other bacteria in that habitat

Question 204

Which of the following is least associated with the others?

Question 7 options:

binary fission

transformation

conjugation

horizontal gene transfer

Answer 204

binary fission

Question 205

Biologists sometimes divide living organisms into two groups: autotrophs and heterotrophs. These two groups differ in ________.

Question 8 options:

the way that they generate ATP

their electron acceptors

their mode of inheritance

their sources of carbon

Answer 205

their sources of carbon

Question 206

Which of the following traits do archaeans and bacteria share?

Question 9 options:

composition of the cell wall and lack of a nuclear envelope

lack of a nuclear envelope and presence of circular chromosome

presence of plasma membrane and composition of the cell wall

composition of the cell wall

Answer 206

lack of a nuclear envelope and presence of circular chromosome

Question 207

Which of the following traits do archaeans and eukaryotes share?

Question 10 options:

presence of introns

presence of a nuclear envelope

sensitivity to streptomycin

presence of peptidoglycan in the cell wall

Answer 207

presence of introns

Question 208

If time, please review the table that compares archaea, prokaryotes, and eukaryotes

Answer 208

mainly less confident in archaea characteristics

Question 209

Community interactions can be classified as whether they…

Answer 209

help, harm, or have no effect on the species involved

Question 210

Interspecific interactions

Answer 210

Between multiple different species

Question 211

Intraspecific interactions

Answer 211

Interactions within a species

Question 212

Competitive interactions

Answer 212

(-/-) interactions that occur when species compete for a resource that limits survival and reproduction. Resources must be in short supply

Question 213

Competitive exclusion

Answer 213

Local elimination of one of the competing species

Question 214

Ecological niche

Answer 214

The position/role of a species within an ecosystem

Question 215

Resource partitioning

Answer 215

Ecologically similar species coexist in a community if there are one or more significant differences in their niches

Question 216

Character displacement

Answer 216

The tendency for characteristics to be more divergent in sympatric populations of two species than in allopatric populations of the same two species

Question 217

Realized vs fundamental niches

Answer 217

Fundamental niches are an entire set of conditions under which an animal can survive and reproduce. Realized niches are a set of conditions actually used

Question 218

Exploitation interactions, and evolutionary adaptations due to these interactions

Answer 218

+/- interactions in which one species benefits by feeding on the other

evolutionary defense mechanisms have been developed to protect prey species from being exploited by predator species

Question 219

Positive interactions

Answer 219

Where one organism/species is benefited, and neither is harmed. Either commensal interactions or symbiotic/mutualistic interactions

Question 220

Two components of species diversity

Answer 220

Species richness: simply the number of species in an area

Relative abundance: the number of individuals per species in the population

Question 221

What are the benefits of having communities that are more diverse species-wise?

Answer 221

They are more productive, more stable, more resilient, and more resistant to invasive species

Question 222

Why are food chains limited?

Answer 222

They’re limited to only 4 or 5 levels, because most energy is lost, and only 10% is passed between consumer

Question 223

Primary producers

Answer 223

Usually plants or phytoplankton (autotrophs, photosynthetic)

Question 224

Primary consumers

Answer 224

Herbivores, zooplankton

Question 225

Secondary, Tertiary and Quaternary consumers

Answer 225

All are carnivores, primary, secondary and tertiary respectively, with tertiary being the “top predator”

Question 226

Keystone species

Answer 226

Species that have low relative abundance but high importance

Question 227

Ecosystem engineers

Answer 227

Create and maintain the habitat they need - they are often keystone species

Question 228

Dominant species vs redundant species

Answer 228

Dominant species are important for their high abundance, while redundant species have an ecological niche that is similar to other species and would not make much of an impact if the species were lost

Question 229

Be able to interpret a food web that includes predation, competition, and facilitation to predict direct and indirect effects of species removal

Answer 229

Pretty easy ,no?

Question 230

Bottom-up model vs. Top-down model

Answer 230

Bottom-up: controlling nutrients (N) controls plants (V) which then controls herbivore numbers (H), which then controls predator numbers (P)

N –> V –> H –> P

Top - down model: controlling predation then controls herbivores, which controls plants, and then controls nutrient levels in soil

P –> H –> V –> N

Question 231

Energetic hypothesis

Answer 231

That 90% of energy is lost when transferred between trophic levels

Question 232

Disturbance (in terms of ecological community)

Answer 232

When something changes a community: removes organisms, or alters resource availability

Question 233

What is the non-equilibrium model when it comes to community disturbances?

Answer 233

Communities are constantly changing after a disturbance

Question 234

What is the intermediate disturbance hypothesis in community disturbance characterization?

Answer 234

Species richness is highest at intermediate levels of disturbance because, at low levels of disturbance, dominant species use up resources and don’t allow less dominant species to thrive, while too much disturbance will not allow any species to thrive

Question 235

Primary succession vs. secondary succession

Answer 235

Primary: Disturbance removes all life and soil from an area

Secondary: Disturbances remove some organisms but soil remains intact

Question 236

Some birds follow moving swarms of army ants in the tropics. As the ants march along the forest floor hunting insects and small vertebrates, birds follow and pick off any insects or small vertebrates that fly or jump out of the way of the ants. This situation is an example of what kind of species interaction between the birds and the ants?

Question 1 options:

consumption

commensalism

parasitism

mutualism

Answer 236

commensalism

Question 237

Use the figures to answer the following question.

In the hypothesis that Chthamalus stellatus (a species of barnacle) is competitively excluded from the lower intertidal zone by Balanus balanoides (another species of barnacle), what could be concluded about the two species?

Question 2 options:

The fundamental and realized niches of B. balanoides are identical, but the fundamental and realized niches of C. stellatus are different.

The fundamental and realized niches of B. balanoides and C. stellatus are different.

The fundamental and realized niches of B. balanoides and C. stellatus are identical.

The fundamental and realized niches of B. balanoides are different, but the fundamental and realized niches of C. stellatus are identical.

Answer 237

The fundamental and realized niches of B. balanoides are identical, but the fundamental and realized niches of C. stellatus are different.

Question 238

As you study two closely related predatory insect species, the two-spot and the three-spot avenger beetles, you notice that each species seeks prey at dawn in areas without the other species. However, where their ranges overlap, the two-spot avenger beetle hunts at night and the three-spot hunts in the morning. When you bring them into the laboratory and isolate the two different species, you discover that the offspring of both species are found to be nocturnal. You have discovered an example of ________.

Question 3 options:

resource partitioning

mutualism

Batesian mimicry

character displacement

Answer 238

resource partitioning

Question 239

The symbols +, -, and 0 are used to show the results of interactions between individuals and groups of individuals. The symbol + denotes a positive interaction, - denotes a negative interaction, and 0 denotes interactions in which individuals are not affected. The first symbol refers to the first organism mentioned. What interactions exist between a lion pride and African wild dogs, if the dogs are found to typically avoid areas with lions?

Question 4 options:

-/-

+/+

0/0

+/-

Answer 239

+/-

Question 240

Character displacement differs from resource partitioning because character displacement ________.

Question 5 options:

is a fundamental difference in feeding behaviors of individuals

is a difference in the niche within a habitat that is preferred to be used by a species

is directly linked to the evolution of genotypes that have allowed alternate resource use

is not the result of competition

Answer 240

is directly linked to the evolution of genotypes that have allowed alternate resource use

Question 241

Which of the following measurements would be most helpful in understanding the structure of an ecological community?

I) determining how many species are present overall

II) determining which particular species are present

III) determining the kinds of interactions that occur among individuals of the same species

IV) determining the abundance of resources available for one species

Question 6 options:

only I and II

only II and IV

only I, II, and III

I, II, III, and IV

Answer 241

only I and II

Question 242

According to bottom-up and top-down control models of community organization, which of the following expressions would imply that an increase in the size of a carnivore (C) population would negatively impact its prey (P) population, but not vice versa? The arrows between species indicate a negative impact toward the population at the arrowhead.

Question 8 options:

P ← C

P → C

C ↔ P

P ← C → P

Answer 242

P ← C

Question 243

Imagine five forest communities, each with one hundred individuals distributed among four different tree species (W, X, Y, and Z). Which forest community would be most diverse?

Question 9 options:

25W, 25X, 25Y, 25Z

40W, 30X, 20Y, 10Z

50W, 25X, 15Y, 10Z

70W, 10X, 10Y, 10Z

Answer 243

25W, 25X, 25Y, 25Z

Question 244

Why do moderate levels of disturbance result in an increase in community diversity?

Question 10 options:

The resulting uniform habitat supports stability, which in turn supports diversity.

Habitats are opened up for less competitive species.

Competitively dominant species infrequently exclude less competitive species after a moderate disturbance.

Less-competitive species evolve strategies to compete with dominant species.

Answer 244

Habitats are opened up for less competitive species.

Question 245

Explain how competition, predation, and mutualism differ in their effects on the interacting populations of two species.

Answer 245

Interspecific competition has a negative effect (-/-) on both species

Predation favors the predator species while negatively affects the prey species (+/-), which is exploitation

Mutualism is where both species benefit +/+

Question 246

According to the principle of competitive exclusion, what outcome is expected when two species with identical niches compete for a resource? Why?

Answer 246

One species will become locally extinct because the other out-competed (and out-reproduced) and successfully claimed all the resources.

Question 247

Imagine that two finch species colonize a new island and are capable of hybridizing. The island contains two plant species, one with large seeds and one with small seeds, growing in isolated habitats. If the two finch species specialize in eating different plant species, would reproductive
barriers be reinforced, weakened, or unchanged in this hybrid zone? Explain.

Answer 247

Reinforced, because each finch species has a separate ecological niche and resources are partitioned, so this will be a concept of habitat isolation where the two finch species will not come in contact much, thus hybrids will not be plentiful

Question 248

What two components contribute to species diversity? Explain how two communities with the same number of species can differ in species diversity.

Answer 248

Species richness: number of species in a community

Relative abundance: number of individuals in each species in comparison to the whole community

Compared to a community with a lopsided relative abundance in favor of one species, a community with a more balanced relative abundance will be considered more diverse

Question 249

How is a food chain different from a food web?

Answer 249

Food chains depict one-way transfers of energy to different trophic levels, while food webs connect multiple food chain pathways to give a broader picture of

Question 250

Consider a grassland with five trophic levels: grasses, mice, snakes, raccoons, and bobcats. If you released additional bobcats into the grassland, how would grass biomass change if the bottom-model applied? If the top-down model applied?

Answer 250

According to the bottom-up model, adding predators would have little effect on grasses/vegetation, but top-down model indicates that increasing predators would decrease racoons, increase snakes, decrease mice, and increase grasses.

Question 251

Rising atmospheric CO2 levels lead to ocean acidification and higher ocean temperatures, both of which can reduce krill abundance. Predict how krill abundance might affect other organisms in the food web shown in figure 54.15. Which organisms are particularly at risk? Explain.

Answer 251

look at 54.15 figure

Question 252

Why do high and low levels of disturbance usually reduce species diversity? Why does an intermediate level of disturbance promote species diversity?

Answer 252

Intermediate levels of disturbance promote species diversity because it opens up habitats for less competitive species. Low disturbance will allow dominant species to thrive, and high disturbance will allow no species to thrive

Question 253

During succession, how might the early species facilitate the arrival of other species?

Answer 253

Increasing the water-holding capacity and fertility of soils or by providing shelter to seedlings from the elements

Question 254

Most prairies experience regular fires, typically every few years. If these disturbances were relatively modest, how would the species diversity of a prairie likely be affected if no burning occurred for 100 years. Explain your answer.

Answer 254

Low level of disturbance - increase of dominant predator, decrease in diversity.

Question 255

Endosymbiosis (in terms of plastid-bearing protists)

Answer 255

Primary symbiosis occurs when an ancient heterotrophic eukaryote swallows a cyanobacteria and they coexist with each other, ending up evolving into red and green algae.

Red alga will undergo secondary endosymbiosis which evolves stramenopiles and alveolates, while green alga undergoes two separate cases of secondary endosymbiosis to form euglenids and chlorarachniophytes

Question 256

4 supergroups of eukaryotes

Answer 256

Excavata, SAR, Archaeplastida, Unikonta

Question 257

Excavates basic characteristics

Answer 257

Modified mitochondria, and unique flagella. They also have a feeding groove on the side of their body, and a cytoskeleton

Question 258

SAR basic characteristics

Answer 258

A highly diverse group of protists that are defined by DNA similarities. and are the most controversial of the four supergroups

Stramenopiles (hairy and smooth flagellum) , Alveolates, and Rhizarians

Question 259

Diatoms

Answer 259

A member of SAR (stramenopile) that has a unique, two-part, glass-like wall of silicon dioxide. Major component of phytoplankton, and highly diverse

They are also important in removing carbon from the atmosphere

Question 260

Archaeplastida

Answer 260

The closest relatives of plants, which includes red and green algae. They bear plastids via evolutionary processes of symbiosis, two lineages

Plants are direct descendants of green algae

Question 261

Dinoflagellates

Answer 261

A member of SAR (Alveolates) that sometimes form symbiotic relationships with coral, but also are the catalyst of “red tides” which are dinoflagellate blooms

Question 262

Unikonta

Answer 262

Include protists that are closely related to fungi / humans. Two clades: ameobozoans, and opisthokonts (which have humans, fungi and related protists)

Question 263

What are some ecological roles of protists?

Answer 263

Two major (and key) roles: they are symbionts and producers
- Symbionts: some nourish coral (dinos) while others digest wood in the guts of termites. Others are unfortunately parasitic

• Producers: some protists are important photosynthetic producers that obtain energy from the sun and convert CO2 to organic compounds

Question 264

The chloroplasts of land plants are thought to have been derived according to which evolutionary sequence?

Question 1 options:

cyanobacteria → green algae → fungi → land plants

red algae → brown algae → green algae → land plants

cyanobacteria → red algae → green algae → land plants

cyanobacteria → green algae → land plants

Answer 264

cyanobacteria → green algae → land plants

Question 265

All protists are ________.

Question 2 options:

eukaryotic

symbionts

mixotrophic

unicellular

Answer 265

eukaryotic

Question 266

Many parasitic members of the excavates lack plastids and have highly reduced mitochondria. Which of the following statements explains these observations?

Question 3 options:

The original, eukaryotic ancestors of these parasites did not engulf prokaryotes.

These parasites live in dark, low-oxygen conditions and therefore loss of genes for plastids and mitochondria did not result in lower fitness.

In the future, natural selection will favor descendants that acquire new plastid genes from today’s prokaryotes.

These parasites live in dark, low-oxygen conditions, and therefore it was adaptive to move all plastid and mitochondrial genes to the nucleus.

Answer 266

These parasites live in dark, low-oxygen conditions and therefore loss of genes for plastids and mitochondria did not result in lower fitness.

Question 267

When a mosquito infected with Plasmodium first bites a human, the Plasmodium ________.

Question 4 options:

cells infect the human liver cells

oocyst undergoes meiosis

gametes fuse, forming an oocyst

cells cause lysing of the human red blood cells

Answer 267

cells infect the human liver cells

Question 268

Which of the following pairs of protists and their ecological roles are correctly matched?

Question 5 options:

apicomplexans—parasites of animals

dinoflagellates—parasites of plants

entamoebas—free-living soil organisms

euglenozoans—primarily mixotrophic

Answer 268

apicomplexans—parasites of animals

Question 269

Dinoflagellates ________.

Question 6 options:

possess two flagella

include species that cause malaria

lack mitochondria

are all autotrophic

Answer 269

possess two flagella

Question 270

You are given an unknown organism to identify. It is unicellular and heterotrophic. It is motile, using many short extensions of the cytoplasm, each featuring the 9 + 2 filament pattern. It has well-developed organelles and two nuclei, one large and one small. This organism is most likely to be a ________.

Question 7 options:

rhizarian

ciliate

diatom

alveolate

Answer 270

ciliate

Question 271

A biologist discovers an alga that is marine, multicellular, and lives at a depth reached only by blue light. This alga is most likely a type of ________.

Question 8 options:

green algae

blue algae- duh

red algae

brown algae

Answer 271

red algae

Question 272

The fact that amoebas are not monophyletic demonstrates that ________.

Question 9 options:

movement by pseudopodia evolved only once

scientists need to continue to investigate the origins and evolutionary history of protists

evolutionary history cannot be discovered

eukaryotes are also not monophyletic and need to be broken into many groups

Answer 272

scientists need to continue to investigate the origins and evolutionary history of protists

Question 273

SAR is a group defined by DNA similarities. This grouping represents ________.

Question 10 options:

a catch-all group that links many unrelated organisms

a demonstration that DNA similarities cannot reveal evolutionary history

a hypothesis about evolutionary history

a paraphyletic group

Answer 273

a hypothesis about evolutionary history

Question 274

What are the key derived characters of plants?

Answer 274

1. Alternation of generations
2. Multicellular, dependent embryos
3. Walled spores produced in sporangia
4. Multicellular gametangia
5. Apical meristems

Question 275

Characteristics of seedless vascular plants

Answer 275

1. Life cycles that are dominated by sporophytes
2. Vascular tissues called xylem and phloem
3. Well-developed roots and leaves
4. Spore-bearing leaves called sporophylls

Question 276

The life cycle of seedless vascular plants

Answer 276

Sporophytes of seedless vascular plants are the larger, more complex generation

mature sporophyte (2n) and sporangium release spores (n) via meiosis –> spore develops into young, and then mature gametophyte (n) –> produces gametes in antheridium and archegonium (n) –> fertilization into zygote (2n) –> new sporophyte (2n) emerges from gametophyte (n)

Question 277

Bryophytes

Answer 277

3 phyla of small, berbaceous (non woody) plants - liverworts, mosses and hornworts

Question 278

Gametangia

Answer 278

Organ in which gametes are produced - found in gametophytes

Question 279

Sporangia

Answer 279

A place where plants make and store spores

Question 280

Cuticle

Answer 280

The outermost layer of plants covers the leaves, fruits, flowers, and nonwoody stems of higher plants. Protects from dangers

Question 281

Two clades of seedless vascular plants

Answer 281

1. Lycophyta: club mosses, spike mosses and quill worts
2. Monilophyta: ferns, horstails, and whisk ferns

Question 282

The most direct ancestors of land plants were probably ________.

Question 1 options:

liverworts and mosses

green algae

kelp (brown alga) that formed large beds near the shorelines

photosynthesizing prokaryotes (cyanobacteria)

Answer 282

green algae

Question 283

About 450 million years ago, the terrestrial landscape on Earth would have ________.

Question 2 options:

had non-vascular, green plants similar to liverworts forming green mats on rock

looked very similar to that of today, with flowers, grasses, shrubs, and trees

been completely bare rock, with little pools that contained cyanobacteria and protists

been covered with tall forests in swamps that would become today’s coal

Answer 283

had non-vascular, green plants similar to liverworts forming green mats on rock

Question 284

Why have biologists hypothesized that the first land plants had a low, sprawling growth habit?

Question 3 options:

They were tied to the water for reproduction, thus needing to remain in close contact with the moist soil.

The ancestors of land plants, green algae, lacked the structural support to stand erect in air.

Land animals of that period were small and could not pollinate tall plants.

There was less competition for space, so they simply spread out flat.

Answer 284

The ancestors of land plants, green algae, lacked the structural support to stand erect in air.

Question 285

You find a green organism in a pond near your house and believe it is a plant, not an alga. The mystery organism is most likely a plant and not an alga if it ________.

Question 4 options:

does not contain vascular tissue

has cell walls that are comprised largely of cellulose

is surrounded by a cuticle

contains chloroplasts

Answer 285

is surrounded by a cuticle

Question 286

A student encounters a pondweed that appears to be a charophyte. Which of the following features would help the student determine whether the sample comes from a charophyte or from some other type of green alga?

Question 5 options:

structure of sperm cells and presence of phragmoplasts

molecular structure of enzymes inside the chloroplasts and rings of cellulose-synthesizing complexes

molecular structure of enzymes inside the chloroplasts and presence of phragmoplasts

structure of sperm cells, presence of phragmoplasts, and rings of cellulose-synthesizing complexes

Answer 286

structure of sperm cells, presence of phragmoplasts, and rings of cellulose-synthesizing complexes

Question 287

The presence of vascular tissue allowed plants to ________.

Question 8 options:

transport nutrients and water from below-ground tissues and use them to protect developing embryos

transport nutrients and water from below-ground tissues to above-ground tissues and grow taller

release toxins into the soil that reduced competition with other plants by poisoning nearby plants

absorb nutrients from the soil and form a symbiosis with fungi

Answer 287

transport nutrients and water from below-ground tissues to above-ground tissues and grow taller

Question 288

Liverworts, hornworts, and mosses are grouped together as bryophytes. Besides not having vascular tissue, what do they all have in common?

Question 9 options:

They are heterosporous.

They are all wind pollinated.

They require water for reproduction.

They can reproduce asexually by producing gemmae.

Answer 288

They require water for reproduction.

Question 289

A botanist discovers a new species of plant in a tropical rain forest. Investigation of its anatomy and life cycle shows the following characteristics: flagellated sperm, xylem with tracheids, separate gametophyte, and sporophyte generations with the sporophyte dominant, and no seeds. This plant is probably most closely related to ________.

Question 10 options:

gymnosperms

flowering plants

mosses

ferns

Answer 289

ferns

Question 290

What are the 3 components of biodiversity?

Answer 290

Genetic diversity, species diversity, and ecosystem diversity

Question 291

What are the main threats to biodiversity?

Answer 291

Habitat loss/fragmentation: the biggest threat to biodiversity, because populations are split into smaller fragments and are more vulnerable to extinction

Introduction of invasive species

Overharvesting: harvesting of organisms at rates exceeding reproduction

Global change: alterations to climate, atmospheric chemistry, and broad ecological systems

Question 292

Describe how population size and genetic diversity increase the health of ecosystems

Answer 292

Smaller population sizes are more prone to extinction vortexes, caused by inbreeding and genetic drift

Maintaining biodiversity helps maintain ecosystems because normal interspecific species interactions can still occur

Question 293

How can humans benefit from and depend on natural ecosystems?

Answer 293

Humans benefit from ecosystems via ecosystem services which include purification of air/water, detoxification/decomp of wastes, crop pollination, pest control, soil preservation, moderation of weather extremes, etc.

Question 294

Describe the prevailing hypothesis about why some introduced species become invasive

Answer 294

Enemy-release hypothesis: in a newly introduced environment, the future invasive species is released without its natural predator, so it can thrive with minimal control

Question 295

The major approaches to habitat conservation that help sustain biodiversity

Answer 295

Creation of corridors to help connect fragments that occur from forest fragmentation

Preserving biodiversity hot spots, which are areas in the world that house many native species that are not found anywhere else

The small population and declining population approaches - focus on small and/or threatened populations and how they are being negatively effected to plan conservation efforts

Question 296

Describe the types of environmental changes arising from human activities (nutrient enrichment, accumulation of toxins, climate change, and ozone depletion)

Answer 296

Nutrient enrichment: Humans remove nutrients from one part of the biosphere, add them in another. Using fertilizer introduces the concept of dead (hypoxic) zones (eutrophication in lakes and oceans along the shore line)

Accumulation of toxins: Harmful substances that remain in ecosystem for a long time, and are passed down through the trophic levels

Climate change

Depletion of atmospheric ozone: depletion of O3 mainly because of chlorofluorocarbons that are emitted by humans

Question 297

Edge

Answer 297

Area of a forest fragment (along the periphery) where the ecosystem/environment is different from the middle

Question 298

Biological accumulation

Answer 298

Accumulation of a toxin in the body of an organism over its lifetime (fat soluble, stored in liver)

Question 299

Biological magnification

Answer 299

Increasing levels of a toxin at higher trophic levels via the energetic hypothesis, where only 10% of energy is passed between trophic levels

Question 300

What is sustainability and why is it relevant for maintaining biodiversity and human well-being?

Answer 300

Sustainability is: meeting the needs of people today without limiting ability of future generations to also meet their needs

requires understanding between life sciences, social sciences and economics / humanities to maintain natural ecosystems but also thrive as a species ourselves

Question 301

Assisted migration

Answer 301

a strategy used by researchers to replenish a depleted small population with low levels of genetic diversity (chicken example)

Question 302

If all individuals in the last remaining population of a particular frog species were all highly related, which type of diversity would be of greatest concern when planning to prevent the species from going extinct?

Question 1 options:

genetic diversity

ecosystem diversity

local diversity

global diversity

Answer 302

genetic diversity

Question 303

Tropical forests are being converted to farm or pasture land at an alarming rate, and one major focus is on the biodiversity and the impact to these ecosystems. What is a direct benefit to humans that helps explain why these forests need to be preserved?

Question 2 options:

The plant diversity provides shade, which lowers global warming.

Natural and undisturbed areas are important wildlife habitats

The diversity could contain novel drugs for consumers.

This diversity provides areas for coffee growing.

Answer 303

The diversity could contain novel drugs for consumers.

Question 304

Ecosystem services include processes that increase the quality of the abiotic environment.

Which of the following processes would fall under this category?

Question 3 options:

Keystone predators have a marked effect on species diversity.

Green plants and phytoplankton produce the oxygen we breathe.

The presence of dams improves flood control.

Bees, flies, and wasps pollinate many plants.

Answer 304

Green plants and phytoplankton produce the oxygen we breathe.

Question 305

Which of the following statements regarding extinction is accurate?

Question 4 options:

The small-population approach is inferior to the declining-population approach if the goal is to conserve the maximum number of species in a given region.

Extinction is occurring at a similar rate now as compared to historical fossil evidence.

Extinctions occur only periodically, separated by long time spans with no extinctions.

A large percentage of species are immune from extinction; however, rates of extinction may increase with continued human impacts.

Answer 305

The small-population approach is inferior to the declining-population approach if the goal is to conserve the maximum number of species in a given region.

Question 306

The human impact that scientists determined has caused the most extinctions on record is ________, and beyond further losses from this impact, the other impact with the largest potential to cause future extinctions is ________.

Question 5 options:

habitat loss; climate change

habitat loss; overharvesting

climate change; habitat loss

introduced species; habitat loss

Answer 306

habitat loss; climate change

Question 307

Introduced species can have deleterious effects on biological communities by ________.

Question 6 options:

reducing erosion increasing the biodiversity in their new region

spreading rapidly in their new region

competing with native species for resources and displacing them

Answer 307

competing with native species for resources and displacing them

Question 308

Suppose you attend a town meeting at which some experts tell the audience that they have performed a cost-benefit analysis of a proposed transit system that would probably reduce overall air pollution and fossil fuel consumption. The analysis, however, reveals that ticket prices will not cover the cost of operating the system when fuel, wages, and equipment are taken into account. As a biologist, you know that if ecosystem services had been included in the analysis, the experts might have arrived at a different answer. Why are ecosystem services rarely included in economic analyses?

Question 7 options:

Federal laws of the United States exclude their inclusion in any cost benefit analysis.

Their cost is difficult to estimate, and people take them for granted.

Ecosystem services only take into account abiotic factors that affect local environments.

They have a low value and are usually not cost effective.

Answer 308

Their cost is difficult to estimate, and people take them for granted.

Question 309

What strategy was used to rescue Illinois prairie chickens from a recent extinction vortex?

Question 8 options:

establishing a nature reserve to protect its habitat nesting grounds

introducing individuals from other populations to increase genetic variation

reducing the population size of its predators and competitors

determining the minimum viable population size by taking into account the effective population size

Answer 309

introducing individuals from other populations to increase genetic variation

Question 310

The primary difference between the small-population approach and the declining-population approach to biodiversity recovery is that ________.

Question 9 options:

declining-population approach would likely involve bringing together individuals from scattered small populations to interbreed in order to promote genetic diversity

small-population approach would investigate and eliminate all of the human impacts on the habitat of the species being studied for recovery

small-population approach is interested in bolstering the genetic diversity of a threatened population rather than the environmental factors that caused the population’s decline

small-population approach applies for conservation biologists when population numbers fall below 500

Answer 310

small-population approach is interested in bolstering the genetic diversity of a threatened population rather than the environmental factors that caused the population’s decline

Question 311

Which of the following is a consequence of biological magnification?

Question 10 options:

Populations of top-level predators are generally smaller than populations of primary consumers.

Toxic chemicals in the environment pose greater risk to top-level predators than to primary consumers.

Only a small portion of the energy captured by producers is transferred to consumers.

The biomass of producers in an ecosystem is generally higher than the biomass of primary consumers.

Answer 311

Toxic chemicals in the environment pose greater risk to top-level predators than to primary consumers.

Question 312

Explain why it is too narrow to define the biodiversity crisis as simply a loss of species.

Answer 312

Not only is it the loss of a species, but a loss of genetic diversity that can dismantle entire ecosystems

Question 313

Why is the minimum viable population size smaller for a genetically diverse population than for a less genetically diverse population?

Answer 313

A more genetically diverse population can withstand selective pressures (given larger gene pool of potentially advantageous traits) than a less genetically diverse population

Question 314

Imagine two populations of a fish species, one in the Mediterranean Sea and one in the Caribbean Sea. Now imagine two scenarios: (1) the populations breed separately and (2) adults of both populations migrate yearly to the North Atlantic to interbreed. Which scenario would result in greater loss of genetic diversity if the Mediterranean population were harvested to extinction? Explain your answer.

Answer 314

1, because gene flow between the two areas would sustain a greater amount of genetic diversity in the 2nd habitat

Question 315

How does the reduced genetic diversity of small populations make them more vulnerable to extinction? Be specific.

Answer 315

Populations with less genetic diversity have smaller genetic pools and therefore are less able to adapt to selective pressures.

Question 316

Give two examples that show how habitat fragmentation can harm species in the long term.

Answer 316

Fragmentation causes populations to be isolated leading to inbreeding / genetic drift, and it can make populations more susceptible to local extinctions due to predation from edge-adapted species.

Question 317

In 2005, at least 10 grizzly bears in the greater Yellowstone ecosystem were killed through contact with people. Most of these deaths resulted from three things: collision with automobiles, hunters (of other animals), and conservation managers killing bears that attack livestock repeatedly. If you were a conservation manager, what steps might you take to minimize such encounters in
Yellowstone?

Answer 317

Reducing contact between humans and bears is the best case scenario, since its impossible to completely eradicate these unfortunate events

Question 318

Suppose a developer proposes to clear-cut a forest that serves as a corridor between two parks. To compensate, the developer also proposes to add the same area of forest to one of the parks. As a
professor ecologist, how might you argue for retaining the corridor?

Answer 318

The corridor allows dispersion and rate of movement between two fragments, ultimately providing more value than increasing the area of either fragment.

Question 319

How can the addition of excess mineral nutrients to a lake threaten its fish population?

Answer 319

Adding nutrients causes algal and other microorganisms to explode, which decreases oxygen levels in the water, which harms fish populations

Question 320

There are vast stores of organic matter in the soils of northern coniferous forests and tundra around the world. Suggest an explanation for why scientists who study global warming are closely
monitoring these stores.

Answer 320

Higher temperatures = organic matter being decomposed more readily = CO2 emissions to go up. CO2 is a GHG, so this area of research is critical to monitoring the progression of global warming

Question 321

Mutagens are chemical and physical agents that induce mutations in DNA. How does reduced ozone concentration in the atmosphere increase the likelihood of mutations in various organisms?

Answer 321

Reduced O3 allows more UV to escape through the atmosphere and alter DNA sequences in organisms, giving rise to more mutations.

Question 322

Thinking about biological magnification of toxins, is it healthier to feed at a lower or higher trophic level? Explain.

Answer 322

Lower trophic level. Toxins are experienced at higher concentrations at higher trophic levels due to chemicals getting passed in high concentrations/quantities through the rest of the trophic levels

Question 323

What is meant by sustainable development?

Answer 323

Working toward long-term prosperity of both human societies AND ecosystems - linking biological sciences with economics and humanities

Question 324

Why is sustainability such an important goal for conservation biologists?

Answer 324

Nature provides us with plenty of ecosystem services in which we benefit: pest control, decomposition of waste, synthesis of organic materials, pollination, etc.

Question 325

Suppose a new fishery is discovered, and you are put in charge of developing it sustainably. What ecological data might you want on the fish population? What criteria would you apply for the fishery’s development?

Answer 325

Knowing the reproductive rate and size of population will be necessary at minimum to calculate a harvest rate. This will allow you to proceed with sustainability in mind

Question 326

How were pollen grains and seeds key adaptations for plants?

Answer 326

Sees provide evolutionary advantage - it is a sporophyte embryo, packaged with a food supply and a protective coat. This allows them to remain dormant until conditions allow for germination (have a supply of stored food, protection).

They can also be transported (and viable during this process) for long distances

Question 327

Gymnosperms vs. Angiosperms

Answer 327

Gymnosperms: naked seeds & cones

Angiosperms: fruit & seeds, with flowers

Question 328

Structure / function of flowers

Answer 328

Stamen (anther/filament) - male portion of the flower, produces pollen. Carpel (simple pistil), which contains stigma, style, and ovary, are the female parts of the plant. Stigma catches pollen and travels down the style into the ovary, where the eggs are.

Sepals are the first whorl of the plant, made to protect the flower during juvenile stage

Petals attract certain types of pollinators

Question 329

Discuss how the flower gives angiosperms a reproductive advantage over gymnosperms

Answer 329

Since flowers attract pollinators to help aid in the plant’s reproductive process, this allows for a more direct process for pollent to reach the ovary vs. gymnosperms’ reliance on wind pollination

Question 330

Ginkgophyta

Answer 330

Type of gymnosperm, creates fleshy fruitlike cones, only one species remains in the phyla

Question 331

Cycadophyta

Answer 331

Type of gymnosperm, often confused with ferns, but usually have a large central cone

Question 332

Gnetophyta

Answer 332

gymnosperms - long, flat leaves on angiosperm-like plants. Some only produce two visible leaves

Question 333

Confierophyta

Answer 333

Needle-like gymnosperms

Question 334

Fruit function of Angiosperms

Answer 334

Fruit is formed when ovary wall thickens and matures - protect seeds, aid in dispersal

Question 335

Which of the following is a major trend in land plant evolution?

Question 1 options:

the trend toward smaller size

the trend toward a gametophyte-dominated life cycle

the trend toward larger gametophytes

the trend toward a sporophyte-dominated life cycle

Answer 335

the trend toward a sporophyte-dominated life cycle

Question 336

In addition to seeds, which of the following characteristics is unique to the seed-producing plants?

Question 2 options:

lignin present in cell walls

pollen

megaphylls

sporopollenin

Answer 336

pollen

Question 337

Arrange the following in the correct sequence, from earliest to most recent, in which these plant traits originated.

Question 3 options:

sporophyte dominance, gametophyte dependence; sporophyte dominance, gametophyte independence; gametophyte dominance, sporophyte dependence

gametophyte dominance, sporophyte dependence; sporophyte dominance, gametophyte dependence; sporophyte dominance, gametophyte independence

gametophyte dominance, sporophyte dependence; sporophyte dominance, gametophyte independence; sporophyte dominance, gametophyte dependence

sporophyte dominance, gametophyte independence; sporophyte dominance, gametophyte dependence; gametophyte dominance, sporophyte dependence

Answer 337

gametophyte dominance, sporophyte dependence; sporophyte dominance, gametophyte independence; sporophyte dominance, gametophyte dependence

Question 338

A researcher has developed two stains for use with seed plants. One stains sporophyte tissue blue; the other stains gametophyte tissue red. If the researcher exposes pollen grains to both stains, and then rinses away the excess stain, what should occur?

Question 4 options:

The pollen grains will be pure red.

The pollen grains will be pure blue.

The pollen grains will have blue interiors and red exteriors.

The pollen grains will have red interiors and blue exteriors.

Answer 338

The pollen grains will have red interiors and blue exteriors.

Question 339

The advantages of the reduced gametophytes in seed plants include ________.

Question 5 options:

development of the seed

protection of the spores from ultraviolet radiation and drying out, and gain of nutrients from the sporophyte

protection from ultraviolet radiation, gain of nutrients from the sporophyte, and protection from drying out

protection from ultraviolet radiation, gain of nutrients from its own photosynthesis, and protection from drying out

Answer 339

protection from ultraviolet radiation, gain of nutrients from the sporophyte, and protection from drying out

Question 340

Unlike almost all ferns, seed plants ________.

Question 6 options:

can photosynthesize

have vascular tissue

produce two kinds of spores

have large gametophytes

Answer 340

produce two kinds of spores

Question 341

The closest relatives of the familiar pine and spruce trees are ________.

Question 7 options:

hornworts, liverworts, and mosses

gnetophytes, cycads, and ginkgos

elms, maples, and aspens

ferns, horsetails, lycophytes, and club mosses

Answer 341

gnetophytes, cycads, and ginkgos

Question 342

The cycads, a mostly tropical phylum of gymnosperms, evolved about 300 million years ago and were dominant forms during the age of the dinosaurs. Though their sperm are flagellated, their ovules are pollinated by beetles. These beetles get nutrition from the pollen and shelter from the microsporophylls. Upon visiting megasporophylls, the beetles transfer pollen to the exposed ovules. In cycads, pollen cones and seed cones are borne on different plants. Cycads synthesize neurotoxins, especially in the seeds, that are effective against most animals, including humans.

Which feature of cycads distinguishes them from most other gymnosperms?

Question 8 options:

They are pollinated by animals.

They have flagellated sperm.

They have flagellated sperm and they are pollinated by animals.

They have exposed ovule

Answer 342

They have flagellated sperm and they are pollinated by animals.

Question 343

Which of the following sex and generation combinations directly produces the fruit of angiosperms?

Question 9 options:

male gametophyte

female sporophyte

female gametophyte

male sporophyte

Answer 343

female sporophyte

Question 344

Arrange the following structures from largest to smallest, assuming that they belong to two generations of the same angiosperm.

Question 10 options:

carpel, embryo sac, ovule, ovary, egg

embryo sac, ovary, carpel, ovule, egg

carpel, ovary, ovule, embryo sac, egg

embryo sac, carpel, egg, ovary, ovule

Answer 344

carpel, ovary, ovule, embryo sac, egg

Question 345

What is the body structure of fungi?

Answer 345

They have multicellular filaments, and single cells (called yeasts). Fungal hyphae form interwoven networks called mycelium

Hyphae are divided into cells by septa (for most fungi) - with pores allowing cell-to-cell movement of organelles

Question 346

Chytridiomycota

Answer 346

Found in terrestrial, freshwater, and marine habitats including hydrothermal vents

They are decomposers, parasites, and or mutualists

Diverged early in fungal evolution. Also have flagellated spores called zoospores, which are unique to all fungi

Question 347

Zygomycetes

Answer 347

Fast growing molds, parasites, or commensal symbionts. Coenocytic hyphae (lacking septa). Asexual sporangia produce haploid spores

Named for their sexually produced zygosporangia, which is the site of karyogamy, then meiosis

Question 348

Glomeromycetes

Answer 348

Nearly all species of glomeromycetes form arbuscular mycorrhizae

Question 349

Ascomycetes

Answer 349

Produce sexual spores in saclike asci contained in fruiting bodies called ascocarps. They vary in size and complexity from unicellular yeasts to cup fungi . Decomposers, pathogens, and symbionts

25% form symbiotic relationships with algae called lichens

Question 350

Basidiomycetes

Answer 350

Mushrooms, puffballs, and shelf fungi. Some form mycorrhizae, some are plant parasites. Some have a fruiting body called the basidiocarp. Many are decomposers of wood

Question 351

Mycorrhizae

Answer 351

mutually beneficial relationships between fungi and plant roots

Question 352

Plasmogamy

Answer 352

the union of the cytoplasms of two parent mycelia.

Question 353

Karyogamy

Answer 353

the fusion of two parent nuclei

Question 354

Dikaryotic

Answer 354

an a cell contains two nuclei, usually unique to ascomycetes and basidiomycetes

Question 355

Fungi have an extremely high surface-to-volume ratio. What is the advantage of this characteristic to an organism that gets most of its nutrition through absorption?

Question 1 options:

This high ratio creates more room inside the cells for additional organelles involved in absorption.

The lower volume prevents the cells from drying out too quickly, which can interfere with absorption.

This high ratio means that fungi have a thick, fleshy structure that allows the fungi to store more of the food it absorbs.

The high ratio allows for more material to be acquired from the surroundings and transported through the cell membrane.

Answer 355

The high ratio allows for more material to be acquired from the surroundings and transported through the cell membrane.

Question 356

If all fungi in an environment that perform decomposition were to suddenly die, then which group of organisms should benefit most, due to the fact that their fungal competitors have been removed?

Question 2 options:

flowering plants

grasses

protists

prokaryotes

Answer 356

prokaryotes

Question 357

When a mycelium infiltrates an unexploited source of dead organic matter, what are most likely to appear within the food source soon thereafter?

Question 3 options:

fungal enzymes

larger bacterial populations

increased oxygen levels

fungal haustoria

Answer 357

fungal enzymes

Question 358

A fungal spore germinates, giving rise to a mycelium that grows outward into the soil surrounding the site where the spore originally landed. Which of the following accounts for the fungal movement, as described here?

Question 4 options:

mycelial flagella

breezes distributing spores

cytoplasmic streaming in hyphae

karyogamy

Answer 358

cytoplasmic streaming in hyphae

Question 359

The adaptive advantage associated with the filamentous nature of fungal mycelia is primarily related to ________.

Question 5 options:

the potential to inhabit almost all terrestrial habitats

the ability to form haustoria and parasitize other organisms

the increased probability of contact between different mating types

an extensive surface area well suited for invasive growth and absorptive nutrition

Answer 359

an extensive surface area well suited for invasive growth and absorptive nutrition

Question 360

Some fungal species live in plants and can kill herbivores that feed on the plant. What type of relationship does this fungus have with its host?

Question 6 options:

mutualistic

predatory

parasitic

commensal

Answer 360

mutualistic

Question 361

At which stage of a basidiomycete’s life cycle would reproduction be halted if an enzyme that prevented the fusion of hyphae was introduced?

Question 7 options:

plasmogamy

karyogamy

germination

fertilization

Answer 361

plasmogamy

Question 362

In most fungi, karyogamy does not immediately follow plasmogamy, which consequently ________.

Question 8 options:

allows fungi to reproduce asexually most of the time

means that sexual reproduction can occur in specialized structures

results in multiple diploid nuclei per cell

results in heterokaryotic or dikaryotic cells

Answer 362

results in heterokaryotic or dikaryotic cells

Question 363

Which feature seen in chytrids supports the hypothesis that they diverged earliest in fungal evolution?

Question 9 options:

coenocytic hyphae

flagellated spores

the absence of chitin within the cell wall

parasitic lifestyle

Answer 363

flagellated spores

Question 364

Arrange the following in order from largest to smallest, assuming that they all come from the same fungus.

Question 10 options:

gill, basidiocarp, mycelium, basidium, basidiospore

mycelium, basidiocarp, gill, basidium, basidiospore

mycelium, gill, basidiocarp, basidium, basidiospore

gill, basidiocarp, basidiospore, basidium, mycelium

Answer 364

mycelium, basidiocarp, gill, basidium, basidiospore

Question 365

What are the key characteristics of animals?

Answer 365

They are multicellular, heterotrophic eukaryotes with tissues that develop from embryonic layers.

Question 366

Gastrulation

Answer 366

When a blastula (formally a zygote) forms a gastrula with different layers of embryonic tissues

Question 367

Blastula

Answer 367

When a zygote undergoes rapid cell division called cleavage, it forms this multicellular, hollow structure.

Question 368

Radial symmetry

Answer 368

Animals that have a top and a bottom, but no front and back, or left and right

Question 369

Bilateral symmetry

Answer 369

They have a dorsal (top) side, a ventral (bottom side), and a left and right side (or anterior and posterior)

Many animals with bilateral symmetry also have sensory equipment,such as a brain, concentrated in their anterior end

Question 370

What three tissues form during embryonic development? Do all animals have all 3?

Answer 370

Ectoderm (germ layer covering embryo’s surface), Endoderm (innermost germ layer, lines developing digestive tube) and mesoderm (the intermediate layer between ecto and endoderm).

some organisms only have ecto and endoderms - diploblastic
Organisms with all three: triploblastic (most have bilateral symmetry)

Question 371

Coelom

Answer 371

a true body cavity derived from the mesoderm (triploblastic animals have these cavities)

Question 372

Coelomates

Answer 372

Animals that possess a true coelom

Question 373

Pseudocoelom

Answer 373

body cavity that is derived from mesoderm and endoderm

Question 374

Acoelomates

Answer 374

Triploblastic animals that lack a body cavity

Question 375

What are body cavities’ functions?

Answer 375

Fluid cushions that suspend organs

Fluid acts like a skeleton which muscles can use to act against and work

Enables internal organs to grow and move independently of the outer body wall

Question 376

What is unique about sponges?

Answer 376

They are animals that lack true body tissues

Question 377

Bilaterians are divided into what three clades?

Answer 377

Deuterostomia (includes acorn worms, sea stars, and chordates), Ecdysozoa (external cytoskeletons), and Lophotrochozoa (have a feeding structure called a lophophore)

Question 378

Eumetazoa

Answer 378

“true animals”

Question 379

5 Important points among living animals are reflected in their phylogeny:

Answer 379

1. All animals share a common ancestor
2. Sponges are sister group to all other animals
3. Eumetazoa (“true animals”) is a clade of animals with tissues
4. Most animal phyla belong to clade Bilateria
5. There are three major clades of bilaterian animals. All are invertebrates except chordata (vertebrates with backbone)

Question 380

How is the conservation of energy and mass useful in ecosystem ecology?

Answer 380

Conservation of mass &energy: matter and energy cannot be created nor destroyed, so they are recycled within ecosystems. They’re open systems, where they absorb energy and mass, but also release heat and waste products

1st law of thermodynamics: energy enters ecosystem as solar radiation, is conserved, then lost from organisms as heat

2nd law of thermodynamics: energy conversions are not efficient, some energy is lost via heat

Question 381

Primary production

Answer 381

The amount of light energy converted to chemical energy by autotrophs during a given time period

Energy and other limiting factors (like nutrients) control primary production

Question 382

Nutrient limitation

Answer 382

Nutrients limit primary production in most oceans/lakes.

Question 383

Limiting nutrient

Answer 383

A nutrient that must be added for production to increase in an area. Nitrogen and phosphorous are usually the nutrients that most often limit marine production

Question 384

Eutrophication

Answer 384

Excessive nutrients/fertilizers run into lakes/oceans via rainwater, plants flourish because of these nutrients leading to algae blooms that block sunlight from reaching other integral plants (depleting oxygen), death of fish and plants lead to decomposition, which further depletes oxygen, leading to hypoxic dead zones.

Question 385

Biogeochemical cycles

Answer 385

Nutrient cycles that involve both biotic and abiotic components

Question 386

To recycle nutrients, an ecosystem must have, at a minimum, ________.

Question 1 options:

producers, primary consumers, secondary consumers, and decomposers

producers and decomposers

producers

producers, primary consumers, and decomposers

Answer 386

producers and decomposers

Question 387

Use the following figure to answer the question. (all arrows point to E at bottom of graph)

Food web for a particular terrestrial ecosystem (arrows represent energy flow and letters represent species)

Examine this food web for a particular terrestrial ecosystem. Which species is most likely a decomposer on this food web?

Question 2 options:

A

B

C

E

Answer 387

E

Question 388

Which of the following organisms is correctly paired with its trophic level?

Question 3 options:

phytoplankton—primary producer

grasshopper—secondary consumer

fungus—primary consumer

cyanobacterium—primary consumer

Answer 388

phytoplankton—primary producer

Question 389

Which of the following has the greatest effect on the rate of chemical cycling within an ecosystem?

Question 4 options:

the secondary production efficiency of the ecosystem’s consumers

the ecosystem’s rate of primary production

the trophic efficiency of the ecosystem

the rate of decomposition in the ecosystem

Answer 389

the rate of decomposition in the ecosystem

Question 390

You own 300 acres of patchy temperate forest mixed with grassy meadows. Which one of the following actions would increase the net primary productivity of the area the most?

Question 5 options:

relocating all of the deer found in the area

introducing 100 rabbits into the area

adding fertilizer to the entire area

planting 500 new trees

Answer 390

planting 500 new trees

Question 391

Suppose you are studying the nitrogen cycling between vegetation, sediments, and water in a pond ecosystem over the course of a month. While you are collecting data, a flock of 100 Canada geese lands and spends the night during a fall migration. What could you do to eliminate error in your study as a result of this event?

Question 6 options:

Find out how much nitrogen is consumed from vegetation and eliminated by a Canada goose over about a 12-hour period and multiply this number by 100; enter this +/- value into the nitrogen budget of the ecosystem.

Find out how much nitrogen is consumed in plant material by a Canada goose over about a 12-hour period, multiply this number by 100, and add that amount to the total nitrogen in the ecosystem.

Put a net over the pond so that no more migrating flocks can land on the pond and alter the nitrogen balance of the pond.

Find out how much nitrogen is eliminated by a Canada goose over about a 12-hour period, multiply this number by 100, and subtract that amount from the total nitrogen in the ecosystem.

Answer 391

Find out how much nitrogen is consumed from vegetation and eliminated by a Canada goose over about a 12-hour period and multiply this number by 100; enter this +/- value into the nitrogen budget of the ecosystem.

Question 392

Why does a vegetarian leave a smaller ecological footprint than an omnivore?

Question 7 options:

Vegetarians need to ingest less chemical energy than omnivores.

There is an excess of plant biomass in all terrestrial ecosystems.

Eating meat is an inefficient way of acquiring photosynthetic productivity.

Fewer animals are slaughtered for human consumption.

Answer 392

Eating meat is an inefficient way of acquiring photosynthetic productivity.

Question 393

Consider the global nitrogen cycle. How are humans altering this cycle?

Question 8 options:

reduction of nitrogen fixation by bacteria

industrial nitrogen fixation

nitrogen lost to the atmosphere

reduction of nitrogen available to terrestrial ecosystems

Answer 393

industrial nitrogen fixation

Question 394

Nitrifying bacteria participate in the nitrogen cycle mainly by ________.

Question 9 options:

converting ammonium to nitrate, which plants absorb

converting nitrogen gas to ammonia

incorporating nitrogen into amino acids and organic compounds

releasing ammonium from organic compounds, thus returning it to the soil

Answer 394

converting ammonium to nitrate, which plants absorb

Question 395

Which of the following would be considered an example of bioremediation?

Question 10 options:

adding nitrogen-fixing microorganisms to a degraded ecosystem to increase nitrogen availability

adding fertilizer to soil poor in nutrients to increase plant growth

dredging a river bottom to remove contaminated sediments

using a bulldozer to regrade a strip mine

Answer 395

adding nitrogen-fixing microorganisms to a degraded ecosystem to increase nitrogen availability

Question 396

Why is the transfer of energy in an ecosystem referred to as energy flow, and not energy cycling?

Answer 396

Energy flows through an ecosystem (solar radiation enters, eventually released as heat). Energy is not recycled through an ecosystem

Question 397

You are studying nitrogen cycling on the Serengeti Plain in Africa. During your experiment, a head of migrating wildebeests graze through your study plot. What would you need to know to measure their effect on nitrogen balance in the plot?

Answer 397

You would need to know how much nitrogen they consumed during their time through the study plot, and also how much nitrogen they eliminated in their urine

Question 398

Use the second law of thermodynamics to explain why an ecosystem’s energy supply must be continually replenished.

Answer 398

The 2nd law states that during energy transfers in an ecosystem, some energy is lost as heat. For this reason, energy will need to be continually replenished by solar radiating sunlight

Question 399

For each of the four biogeochemical cycles (water, nitrogen, phosphorus, carbon), draw a simple
diagram that shows one possible path for an atom of that chemical from abiotic to biotic reservoirs
and back.

Answer 399

DRAW THE CYCLES

Question 400

Why does deforestation of a watershed increase the concentration of nitrates in streams draining
the watershed?

Answer 400

The deforestation of trees stops nitrate updake in the soil, allowing nitrates to accumulate there. The nitrate is washed away by precip and ends up in streams

Question 401

The main goals of restoration ecology

Answer 401

The main goal is to restore degraded ecosystems to a more natural state

Question 402

How are Cnidarians characterized body plan wise?

Answer 402

They are diploblastic, and have radial symmetry.

Question 403

Gastrovascular cavity (Cnidarians)

Answer 403

It is a sac with a central digestive compartment

Question 404

Cnidarians have two variations of body plan

Answer 404

A polyp vs Medusa

Polyp: adheres to substrate on opposite end from anus/mouth opening

Medusa: bell-shaped body with its mouth on underside

Question 405

What is unique about phylum Lophotrochozoans?

Answer 405

They have the widest range of animal body forms

Question 406

• Construct a phylogenetic tree that summarizes the current understanding of the relationships among the major animal groups

Answer 406

Phone picture

Question 407

Alimentary canal

Answer 407

The path of the entire digestive system, from mouth to anus

Question 408

Which of the following is (are) unique to animals?

Question 1 options:

flagellated gametes

nervous system signal conduction and muscular movement

the structural carbohydrate, chitin

heterotrophy

Answer 408

nervous system signal conduction and muscular movement

Question 409

The larvae of some insects are merely small versions of the adult, whereas the larvae of other insects look completely different from adults, eat different foods, and may live in different habitats. Which of the following is most directly involved in the evolution of these variations in metamorphosis?

Question 2 options:

) the origin of a brain

the evolution of meiosis

changes in the homeobox genes controlling early development

artificial selection of sexually immature forms of insects

Answer 409

changes in the homeobox genes controlling early development

Question 410

Which of the following is a feature of the “tube-within-a-tube” body plan in most animal phyla?

Question 3 options:

The outer tube consists of digestive organs.

The mouth and anus form the ends of the inner tube.

The two “tubes” are separated by tissue that comes from embryonic endoderm.

The outer tube consists of a hard exoskeleton.

Answer 410

The mouth and anus form the ends of the inner tube.

Question 411

You have before you a living organism, which you examine carefully. Which of the following should convince you that the organism is acoelomate?

Question 4 options:

It is triploblastic.

It has bilateral symmetry.

It possesses sensory structures at its anterior end.

Muscular activity of its digestive system distorts the body wall.

Answer 411

Muscular activity of its digestive system distorts the body wall.

Question 412

An organism that exhibits a head with sensory equipment and a brain probably also ________.

Question 5 options:

has a coelom

is bilaterally symmetrical

is segmented

is diploblastic

Answer 412

is bilaterally symmetrical

Question 413

Healthy corals are brightly colored because they ________.

Question 6 options:

secrete colorful pigments to protect themselves from ultraviolet light

build their skeletons from colorful minerals

secrete colorful pigments to attract mates

host symbionts with colorful photosynthetic pigments

Answer 413

host symbionts with colorful photosynthetic pigments

Question 414

You find what you believe is a new species of animal. Which of the following characteristics would enable you to argue that it is more closely related to a flatworm than it is to a roundworm?

Question 7 options:

It is shaped like a worm.

It has no coelom.

It is a suspension feeder.

It has a mouth and an anus.

Answer 414

It has no coelom.

Question 415

Which characteristic is shared by cnidarians and flatworms?

Question 8 options:

radial symmetry

a digestive system with a single opening

dorsoventrally flattened bodies

a distinct head

Answer 415

a digestive system with a single opening

Question 416

Molecular studies have changed many of the phylogenetic relationships previously identified by morphological studies. These changes indicate that ________.

Question 9 options:

molecular studies are extremely time consuming and expensive and really don’t add additional information to our understanding of evolutionary history

molecular and morphological studies rarely agree

molecular studies add additional information to morphological studies and improve our understanding of evolutionary history

molecular studies are less reliable than morphological studies

Answer 416

molecular studies add additional information to morphological studies and improve our understanding of evolutionary history

Question 417

A terrestrial animal species is discovered with the following larval characteristics: exoskeleton, system of tubes for gas exchange, and modified segmentation. A knowledgeable zoologist should predict that the adults of this species would also feature ________.

Question 10 options:

a sessile lifestyle

two pairs of antennae

eight legs

an open circulatory system

Answer 417

an open circulatory system

Question 418

Key features of a chordate

Answer 418

1. notochord
2. dorsal, hollow nerve cord
3. pharyngeal slits or clefts
4. Muscular post-anal tail

Question 419

Evolutionary history of vertebrates

Answer 419

Earliest vertebrates lacked jaws, lacked a backbone, and rudimentary vertebrae during development (hagfishes, lampreys)

Question 420

Gnathostomes

Answer 420

Vertebrates that have jaws (sharks, some fish, amphibians, reptibles, birds, mammals)

Question 421

Amniotes

Answer 421

Tetrapods that have terrestrially adapted eggs

Question 422

Amniotic egg

Answer 422

Terrestrially adapted eggs from amniotes, which is a key adaptation to life on land (reptiles)

Question 423

Monotremes

Answer 423

Small group of egg laying mammals (echidnas and platypus)

Question 424

Marsupials

Answer 424

Embryo develops within mother’s uterus and is nourished by placenta, but born very early and completes development in an maternal external pouch (kangaroos, koalas, opossums)

Question 425

Eutherians

Answer 425

More complex placenta, and complet embryonic development in the uterus

Question 426

Which of the following is a characteristic of all chordates at some point during their life cycle?

Question 1 options:

jaws

post-anal tail

vertebrae

four-chambered heart

Answer 426

post-anal tail

Question 427

Vertebrates and tunicates share ________.

Question 2 options:

jaws adapted for feeding

a notochord and a dorsal, hollow nerve cord

a high degree of cephalization

the formation of structures from the neural crest

Answer 427

a notochord and a dorsal, hollow nerve cord

Question 428

Suppose, while out camping in a forest, you found a chordate with a long, slender, limbless body slithering across the ground near your tent. This critter could be ________.

Question 3 options:

a lamprey

an amphibian

a skate

a mammal

Answer 428

an amphibian

Question 429

A trend first observed in the evolution of the earliest tetrapods was ________.

Question 4 options:

the amniotic egg

the appearance of jaws

the mineralization of the endoskeleton

feet with digits

Answer 429

feet with digits

Question 430

Fossils of the earliest tetrapods should ________.

Question 5 options:

show evidence of having produced shelled eggs

show evidence of internal fertilization

indicate limited adaptation to life on land

feature the earliest indications of the appearance of jaws

Answer 430

indicate limited adaptation to life on land

Question 431

What is believed to be the most significant result of the evolution of the amniotic egg?

Question 6 options:

Embryos are protected from predators.

Tetrapods can now function with just lungs.

Tetrapods are no longer tied to the water for reproduction.

Newborns are much less dependent on their parents.

Answer 431

Tetrapods are no longer tied to the water for reproduction.

Question 432

Which of the following characteristics evolved independently in mammals and birds?

Question 7 options:

bone

jaws

endothermy

amniotic eggs

Answer 432

endothermy

Question 433

During chordate evolution, what is the sequence (from earliest to most recent) in which the following structures arose?

Question 8 options:

jaws, paired fins, paired fins, swim bladder, four-chambered heart

jaws, paired fins, swim bladder, four-chambered heart, amniotic egg

paired fins, jaws, swim bladder, amniotic egg, four-chambered heart

paired fins, amniotic egg, four-chambered heart, jaws, swim bladder

Answer 433

paired fins, jaws, swim bladder, amniotic egg, four-chambered heart

Question 434

Primate evolution and behavior, such as hunting skills, have been directed in part by the development of depth perception. What anatomical change made depth perception possible

Question 9 options:

location of the eyes at the front of the head

diurnal activity

the formation of compound eyes

a larger brain

Answer 434

location of the eyes at the front of the head

Question 435

Unlike eutherians, both monotremes and marsupials ________.

Question 10 options:

lack nipples

have some embryonic development outside the uterus

lay eggs

are found in Australia and Africa

Answer 435

have some embryonic development outside the uterus