PowerPoint for Fourth Exam

Question 1

Why is animal diversity disappearing?

Answer 1

Speciation (the formation of new species) is slower than extinction. The incredible diversity of animals has evolved over hundreds of millions of years but can be quickly destroyed. The number one cause of destruction of species is habitat loss.

Question 2

What is an animal?

Answer 2

Animals are eukaryotic, multicellular, heterotrophic organisms that obtain nutrients by eating.

Question 3

What are the three types of fish?

Answer 3

Jawless: called agnathans, and lack jaws. Two types of jawless fishes survive today–hagfishes and lampreys. Jawless fishes swallow their food whole.

Cartilaginous: have a flexible skeleton made of cartilage; move by bending its body, not by bending its fins. Example of cartilaginous fishes are sharks and rays.

Bony: skeleton is reinforced by calcium salts. They have a lateral line system, a keen sense of smell, and excellent eyesight. They also have a protective flap called the operculum on each side of their head to help them breathe.

Question 4

Do amphibians live on land? In the water?

Answer 4

The Greek word amphibios means “living a double life.” Most amphibians exhibit a mixture of aquatic and terrestrial adaptations. Most species are tied to water because their eggs, lacking shells, dry out quickly in the air.

Question 5

How are reptiles adapted to live totally on land?

Answer 5

Reptiles and mammals are called amniotes, which are named after the amniotic egg, a fluid-filled egg with a waterproof shell that encloses the developing embryo. This egg acts as a pond that enables amniotes to complete their life cycle on land.

They also have scales to prevent dehydration, and lungs to help them breathe.

Question 6

How are Class Aves modified for flight?

Answer 6

The bones are structured in a way that makes birds strong but light. (The wings of airplanes are constructed in the same way.) They’re light and hollow, and birds don’t have many bones.

Birds are endotherms, which means they use their own metabolic heat to maintain a warm, constant body temperature. (Ectotherms are basically the opposite; they rely on external heat to warm up their bodies. They cannot keep up a constant body temperature through internal processes.)

Feathers are another feature that help birds with flight.

Question 7

What traits do all mammal species share?

Answer 7

All mammal species share the same two features: hair (which insulate the body and help maintain a warm, constant internal temperature) and mammaries (which produce milk that nourishes the young).

Question 8

What are the three types of mammals?

Answer 8

Monotremes: the egg-laying mammals (ex: platypus)

Marsupials: the pouched mammals (ex: kangaroo); babies are born alive but stays inside mom’s body.

Placentals/eutherians: almost all mammals are born externally (ex: humans, dogs, cats, etc.)

Question 9

How were primates shaped by living in trees?

Answer 9

Primates have limber shoulder joints, which make it possible to swing from branch to branch. Their hands can hang on to branches and manipulate food. Their eyes enhance depth perception. Parental care is another thing that primates shaped by living in trees: more primates have single births and nurture their offspring for a long time.

Question 10

What are the anthropoids? Did humans come from monkeys?

Answer 10

Anthropoids are members of a primate group made up of the apes (gibbons, orangutans, gorillas, chimpanzees, and bonobos), monkeys, and humans.

Humans did not come from monkeys. It is a common misconception that humans have evolved through “ladders.” Human phylogeny is more like a multibranched bush than a ladder, because at times several other hundred species coexisted.

Question 11

What does ecology study?

Answer 11

Ecology is the scientific study of the interactions between organisms and their environments.

Question 12

What are the three levels of ecology?

Answer 12

Population: a group of individuals of the same species living in a particular geographic area. Population ecology concentrates mainly on factors that affect population density and growth.

Community: consists of all the organisms that inhabit a particular area; it is an assemblage of populations of different species. Community ecology focuses on how interactions between species, such as predation and competition, affect community structure and organization.

Ecosystem: includes all of the abiotic factors in addition to the community of species in a certain area. Ecosystem ecology concerns energy flow and the cycling of chemicals among the various biotic and abiotic factors.

Question 13

What is the biosphere?

Answer 13

The biosphere is the global ecosystem–the sum of all the planet’s ecosystem, or all of life and where it lives. It is the most complex level in ecology, and includes the atmosphere, the land, lakes and streams, caves, and the oceans.

Question 14

What does abiotic mean and what are some of its factors?

Answer 14

An abiotic factor is a nonliving component of an ecosystem, such as air, water, light, minerals, or temperature.

Sunlight: solar energy powers nearly all ecosystems

Water: aquatic organisms must maintain water balance; terrestrial organisms must prevent dehydration

Temperature: environmental temperature affects metabolic rate, and affects ectothermic organisms

Wind: some organisms depend on nutrients blown to them by wind. Some plants depend on wind to disperse pollen and seeds.

Rocks and soil: soil variation contributes to the patchiness of terrestrial landscapes (plants cannot grow here because sand/soil cannot hold water very well). In streams, rivers, and lakes, the soil affects water chemistry (streams: pure water, almost no chemistry, no species live there; rivers: mucky water, a lot of chemistry, lots of species live there).

Question 15

How are ecology and evolution tightly linked?

Answer 15

Evolutionary adaptation via natural selection results from the interactions of organisms with their environments; the difference is time. In other words, evolution results from ecology.

Question 16

What is population density and how do we measure it?

Answer 16

Population density is the number of individuals of a species per unit area or volume of the habitat. Ecologists use census techniques to measure the population density.

For example, ecologists might estimate the density of alligators in the Florida Everglades based on a count of individuals in a few sample plots of 1 km-squared each. The larger the number and size of sample plots, the more accurate the estimates.

Question 17

What are the three dispersion patterns?

Answer 17

Dispersion means spread across an area. There are three patterns of dispersion.

Clumped pattern: individuals aggregate in clumps (school of fish)

Uniform pattern: results from interactions among the individuals of a population

Random pattern: individuals are spaced in a pattern-less, unpredictable way (trees).

Question 18

What are the two types of population growth?

Answer 18

Two types of population growth are…

Exponential growth: grow, multiply quickly (such as bacteria). In the exponential growth model, the population size of each new generation is calculated by multiplying the current population size by a constant factor that represents the number of births minus the number of deaths. The rate of population growth increases with population size.

Logistic growth: increases rapidly, then slows down (which is mostly seen in nature). The growth rate decreases as the population size approaches carrying capacity. When the population is at carrying capacity, the growth rate is zero.

Question 19

What is carrying capacity?

Answer 19

Carrying capacity is the number of individuals that an environment can carry.

Question 20

Why do some populations cycle?

Answer 20

Some populations have regular “boom and bust” cycles. “Booms” characterized by rapid exponential growth are followed by “busts,” during which the population falls back to a minimal level. Some populations cycle due to:

Predator-prey interaction–for example, every time hare populations grow, lynx populations grow; when hare populations decrease, so do lynx populations.

Weather–cycles may be caused by winter food shortages that result from overgrazing.

Food availability–fluctuations in the hare’s food supplies may be another cause of population cycles.

Question 21

What are the three kinds of survivorship curves?

Answer 21

A survivorship curve is a plot of the number of individuals still alive at each age in the maximum life span.

Type I (negative aging): more likely chance of dying in elderly ages than in young ages.

Type II (neutral aging): equal chance of dying at any age

Type III (positive aging): more likely chance of dying in yong ages than in elder ages

Question 22

What is a community?

Answer 22

A community is an assemblage of species living close enough together for potential interaction.

An organism’s biotic environment includes not just individuals from its own population, but also populations of other species living in the same area.

Question 23

What are the two components of community diversity?

Answer 23

The diversity of a community has two components:

Species richness–the number of different species in a community; one component of species diversity.

Species evenness–the variety of species that make up a biological community; the number and relative abundance of species in a biological community.

Question 24

Food chain or food web?

Answer 24

A food chain is the sequence of food transfer between trophic levels. It is part of the trophic structure.

A food web includes the feeding relationships in a community.

Question 25

What does interspecific refer to? Intraspecific?

Answer 25

Interspecific interactions are between species. Some interactions can be negative for both species (two populations in a community vie for a resource such as food or space); positive for both species (an example would be the interactions between flowers and their pollinators); or neutral (one species exploits another species as a source of food, which can be beneficial for one species but harmful to the other).

Intraspecific interactions are among species. It ultimately limits population growth.

Question 26

Why do species compete? Over what?

Answer 26

Interspecific competition is very common and occurs between two or more species that compete for limited resources (such as food, water, habitat, and mates).

Question 27

What is a niche? What does the competitive exclusion principle say?

Answer 27

An ecological niche is defined as its total use of the biotic and abiotic resources in its environment.

The competitive exclusion principle says two species cannot coexist in a community if their niches match. Possible outcomes can include extinction of one species or evolution of one species to use different resources. Russian ecologist G. F. Gause came up with this principle.

Question 28

How is a predator different from a parasite?

Answer 28

Predators are organisms that kill and eat other organisms (prey).

A parasite lives on or in a host from which it obtains nourishment. Interactions with their hosts (animals or plants) can be harmful for one species (hosts) and beneficial for the other (parasite).

Question 29

What are passive defenses? Active defenses?

Answer 29

Passive defenses include hiding.

Active defenses are escaping or defending.

Question 30

What is mutualism?

Answer 30

Mutualism is when both species benefit from an interaction. Some mutualisms occur between symbiotic species–those in which the organisms have a close physical association with each other. For example, in symbiotic root-fungus associations, the fungus delivers mineral nutrients to the plant and receives organic nutrients in return.

Question 31

What is succession?

Answer 31

The process of biological community change resulting from disturbance; transition in the species composition of a biological community, often following a flood, fire, or volcanic eruption.

When ecological succession begins in a virtually lifeless area with no soil, it is called primary succession.

Secondary succession occurs where a disturbance has destroyed an existing community but left the soil intact.

Question 32

What is trophic structure?

Hint: food webs, energy flow

Answer 32

A trophic structure is the feeding relationships among the various species in a community. A community’s trophic structure determines the passage of energy and nutrients from plants and other photosynthetic organisms to herbivores and then to predators.

A food chain is the sequence of food transfer between trophic levels.

Bottom of food chains are autotrophs, or producers. Next are primary consumers (herbivores), which eat plants, algae, or phytoplankton. Next are secondary consumers (carnivores), which eat the consumers from the level below. Higher trophic levels include tertiary consumers (third-level consumers). Next are quarternary consumers (fourth-level consumers).

Question 33

Which chemicals cycle through an ecosystem?

Answer 33

Chemical cycling is the use and reuse of chemical elements such as carbon and nitrogen within the ecosystem.

Chemical elements such as carbon and nitrogen are cycled between the abiotic components of the ecosystem, including air, water, and soil, and the biotic components of the ecosystem. Plants acquire these elements in inorganic form from the air and soil and fix them into organic molecules. Animals consume some of these organic molecules.

Question 34

What are biomes?

Answer 34

A biome is a major terrestrial or aquatic life zone, characterized by vegetation type in terrestrial biomes and the physical environment in aquatic biomes. Biomes are the major types of ecosystems that cover large geographic regions of the Earth.

Question 35

What is the #1 cause of species extinction? #2?

Answer 35

The number one cause of species extinction is habitat loss.

The number two cause of species extinction is introduced species. If a new species is introduced into an environment, it may have the potential to wipe out other species from that environment. (ex: toads in Australia)

Question 36

What is global warming? What causes it?

Answer 36

Global warming is the gradual increase in the overall temperature of the Earth’s atmosphere generally caused by the burning of fossil fuels (carbon dioxide, chlorofluorocabons, etc.)

Question 37

What impact does too much nitrogen/phosphate have in an ecosystem?

Answer 37

Too much nitrogen and phosphate added into the ecosystem causes a heavy growth of algae. If there is too much algae in a pond, for example, no sunlight could enter the pond and nourish the plants inside the water. This, in turn, causes the plants to die, which causes animals (such as fish) to die.

Question 38

What is the water cycle?

Answer 38

The water cycle is the cycle of processes by which water circulates between the earth’s oceans, atmosphere, and land, involving precipitation as rain and snow, drainage in streams and rivers, and return to the atmosphere by evaporation and transpiration.

Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere.

Question 39

What is biological magnification?

Answer 39

Biological magnification is the accumulation of persistent chemicals in the living tissues of consumers in food chains.

Question 40

What damaged the ozone layer? How?

Answer 40

Our protective ozone layer started thinning due to the build up of chlorofluorocarbons, which are any of a class of compounds of carbon, hydrogen, chlorine, and fluorine (typical gases used in refrigerants and aerosol sprays).

Question 41

Why are current species’ extinctions of concern?

Answer 41

The current mass extinction is caused by human activity, and is broader and faster than other past extinctions.

Question 42

What is the #3 cause of species extinction? Why do we need biodiversity?

Answer 42

The #3 cause of species extinction is over-exploitation of wildlife. This means that humans over-harvest (taking more from the land than it can replace) that exceed the ability of populations to rebound. Humans rely on biodiversity for food, clothing, and shelter, and oxygen, soil fertility, and medicinal substances.

Question 43

What is conservation energy?

Answer 43

Conservation energy is a goal-oriented science that seeks to understand and counter the loss of biodiversity. It deals with relationships between biology and society.

Question 44

What are hot spots? Endemics?

Answer 44

A biodiversity hot spot is a small geographic that contains a large number of threatened or endangered species and an exceptional concentration of endemic species (those found nowhere else).

Endemic species are a species whose distribution is limited to a specific geographic area.

Question 45

What is sustainable development?

Answer 45

Sustainable development is the long-term prosperity of human societies and the ecosystems that support them.

Question 46

What is population fragmentation?

Answer 46

The splitting and consequent isolation of portions of populations by habitat destruction.

Question 47

What is a movement corridor?

Answer 47

A narrow strip or series of small clumps of quality habitat connecting otherwise isolated populations.

Corridors promote dispersal and help sustain populations. They are especially important to species that migrate between different habitats.

Question 48

What are zoned reserves?

Answer 48

A zoned reserve is an extensive region of land that includes one or more areas undisturbed by humans (only means that you can’t modify it). An example would be a national park.

The areas surrounding zone reserves are buffer zones that support both agriculture and tourism.