Test 2 Flashcards
(87 cards)
1
Q
What is ecology?
A
The study of relationships between organisms and environment
2
Q
What is organismal ecology?
A
The study of an organism’s relationship with its environment (biotic and abiotic)
3
Q
What is population ecology?
A
The study of interactions between members of the same species.
4
Q
Define an abiotic factor and give some examples.
A
Non-living physical and chemical elements. Ex: water, air, soil, sunlight, minerals, etc.
5
Q
Define a biotic factor and give some examples.
A
Living organisms. Ex: animals, plants, fungi, etc.
6
Q
Define population
A
Groups of individuals of the same species in one place
7
Q
What are the 3 characteristics of a population?
A
- Range/area
- Pattern of spacing of individuals
- Change in size through time
8
Q
Define density-dependent factors and give some examples.
A
Population regulation where the denser a population is, the greater its mortality rate (negative feedback)(often biotic)
Ex: Predation, inter- and intraspecific competition, accumulation of waste, diseases, etc.
9
Q
Define density-independent factors and give some examples.
A
Population regulation where the population is influenced no matter what its density is.
Ex: weather, natural disasters, pollution, and other chemical/physical conditions. (often abiotic)
10
Q
What is population demography, and how is it done?
A
-The quantitative study of populations to see how populations change size over time.
-Populations are broken down into parts, and birth and death rates of a specific age are considered.
11
Q
Population growth is most influenced by the number of what?
A
Females
12
Q
What are generation times?
A
The average interval between an individual’s birth and its offspring’s birth. (shorter generation times mean an increase in size more quickly.)(larger organisms have longer generations times normally)
13
Q
What is a Cohort?
A
Group of individuals of the same age.
14
Q
What is Fecundity?
A
Number of offspring produced in a standard time
15
Q
What is mortality?
A
Number of individuals removed from the population.
16
Q
What is the mortality rate formula?
A
dx/nx (number of deaths during time period/number alive at the start of a time period)
17
Q
Define survivorship and survivorship curve.
A
-percent of the original population surviving to a given age.
-Graph of number of individuals surviving at each age interval.
18
Q
What is a type 1 curve species?
A
The species have a small number of offspring and provide lots of parental care to make sure those offspring survive. This leads to few offspring that survive for a long time. (humans)
19
Q
What is a type 2 curve species?
A
Organisms of this species die more or less equally at each age interval. (birds)
20
Q
What is a type 3 curve species?
A
The species have lots of offspring at once but don’t provide much care for the offspring. This leads to a high amount of offspring mortality, with few surviving.
21
Q
What do life tables show?
A
The probability of survival and reproduction through a cohort’s life.
22
Q
Which of the following components is NOT typically used to construct a life table?
Birth rates, death rates, survival rates, or fertility rates.
A
fertility rates
23
Q
Populations often remain what regardless of number of offspring born?
A
The same size.
24
Q
What is the difference between Immigration and Emigration?
A
Immigration: individuals entering a population
Emigration: individuals leaving a population
25
What is a carrying capacity?
(k): The maximum number of individuals that an environment can support.
26
What is a J curve?
The curve of exponential growth in a population. There are no checks on the population's growth.
27
What is logistical growth?
The growth of a population as it reaches its environment's carrying capacity. Its curve will resemble a S shape.
28
What type of growth do humans have?
exponential
29
What is an ecological footprint?
The amount of productive land required to support an individual at the standard of living of a particular population through the course of his/her life.
30
What is a dominant species?
The most abundant species.
31
What is a keystone species?
The most influential species with respect to trophic levels.
32
What is a foundation species?
A species that allows other species to inhabit an area by altering the environment.
33
What is community ecology?
The study of interacting populations of species living within a particular area or habitat.
34
What is Intraspecific competition?
Competition within a species.
35
What is Interspecific competition?
Competition between species.
36
What is Interference?
Direct, physical interactions over resources.
37
What is exploitative?
Interact indirectly by consuming the same resources.
38
What is the competitive exclusion principle?
Two species cannot occupy the same niche in a habitat. (different species can't coexist in a community if they are competing for all the same resources.)
39
What is the difference between symmetric and asymmetric growth?
When two species' populations grow separate from each other, they are symmetric S curves. However, when they are together, one out-competes the other, leading to asymmetric growth between the two species.
40
What is a niche?
The total range of conditions under which an individual (or population) lives and replaces itself
41
What is a realized niche?
The actual set of conditions under which an organism exists.
42
What is a fundamental niche?
The entire set of optimal conditions under which an organismic unit can live and replace itself.
43
What is resource partitioning?
Species evolve to share resources.
44
Give an example of chemical defenses in Animals
Monarch butterfly caterpillars eat milkweed & dogbane and incorporate the cardiac glycosides from these plants so that birds get sick when they eat the monarchs.
45
What is aposematic coloration?
The use of bright coloration to warm predators to its defenses of being toxic, foul-tasting, or smelling. Etc.
46
What does camouflaged or cryptic colored mean?
The animal is nonpoisonous and blends into its surroundings.
47
What are the two types of mimicry?
Batesian and Mullerian
48
What is Batesian mimicry?
A harmless species imitates warning signals of harmful species.
49
What is Mullerian mimicry?
Related or unrelated poisonous species that share a predator come to resemble one another's warning signals.
50
What are some examples of defense mechanisms?
Chemical, aposematic coloration, camouflaged, cryptic coloring, mimicry, schooling, looking bigger, and spines, thorns, quills, Etc.
51
What are the three types of species interactions?
commensalism, parasitism, and mutualism
52
What is a mutualistic relationship, and give examples.
-It is a relationship where both species/animals benefit.
-Ex: clownfish hide and live in sea anemones, and in return, they clean the sea anemones
-Ex: cleaner shrimp eat the parasites off of organisms, the shrimp gets a meal and the organism gets rid of parasites
-Ex: Termites and their gut flagellates: termites cannot normally digest wood, but with the help of gut flagellates, they can digest wood and give the gut flagellates a home.
53
What is commensalism, and what are some examples?
-Commensalism relationships occur when one species/animal benefits and the other is unaffected.
-Ex: The remora and sharks, the remora sticks to the shark and waits until the shark is done eating something to feed on the scraps.
54
What are the four types of parasitism?
Endoparasites, Ectoparasites, parasitoidism, endosymbiont (usually mutualistic)
55
Define an ecosystem.
All organisms and the environment in which they live and interact. (biotic + abiotic)
56
What are the four main abiotic biogeochemical cycles?
Water, carbon, Nitrogen, and phosphorus
57
What are the important steps in the nitrogen cycle?
Atmospheric nitrogen (N2) goes through nitrogen fixation to enter the soil. The nitrogen then goes through Ammonification by bacteria and fungi to become ammonia (NH4). The ammonia then goes through nitrification by bacteria to become nitrite (NO2) and then nitrate (NO3). Finally, the nitrogen is returned to atmospheric nitrogen gas through denitrification by bacteria.
58
What is richness?
Number present.
59
What is abundance?
number of individuals per species
60
What is relative abundance?
How common or rare a species is relative to others.
61
What is diversity?
Species richness and evenness of species' abundances.
62
What is evapotranspiration?
The release of water into the atmosphere as water vapor, by evaporation, transpiration, and respiration.
63
Can energy be recycled?
No.
64
What are some examples of energy?
heat, light, chemical-bond energy, motion
65
What is the first law of thermodynamics?
Energy is neither created nor destroyed. It can only change forms.
66
What is the second law of thermodynamics?
Some chemical bond or light energy is lost to heat energy (entropy).
67
What is a trophic level?
A group of organisms that occupy the same level in the food chain. (each level differs in nutritional relationship with the primary energy source.)
68
What are autotrophs?
"self-feeders" assemble inorganic precursors into the array of organic compounds from which they are made.
69
What are photoautotrophs?
energy from light
70
What are Chemoautotrophs?
Energy from inorganic molecules.
71
What are Heterotrophs?
Obtain organic compounds by consuming other organisms
72
What are mixotrophs?
Obtain energy from organic and inorganic compounds (get energy from sunlight and from eating other organisms)
73
What are the different trophic levels?
Primary producers: autotrophs
Herbivores: Vegetation Consumers
Primary carnivores: Consume Herbivores
Secondary carnivores: Consume Primary Carnivores
Detritivores: Consume Organic Detritus
Decomposers: Decompose Decaying Matter
74
What is gross primary productivity?
The rate at which primary producers incorporate energy from the sun.
75
What is net primary productivity?
Energy that remains in primary producers after respiration and heat loss.
76
What percent per year of incoming solar radiant energy is captured by primary producers?
1 percent. 34 percent is reflected back into space by clouds, and 66 percent is reflected into space by the Earth itself.
77
What is a limiting nutrient?
Nutrients in the shortest supply and put a limit on growth.
78
What is the limiting nutrient for terrestrial and aquatic ecosystems?
Nitrogen and phosphorus.
79
What is the limiting nutrient for algal populations in ~1/3 of the world's oceans?
Iron.
80
What is the ten percent rule/law?
During the transfer of energy down trophic levels, only ~10% of energy is stored as biomass
81
What percent of energy captured by photosynthesis passes through to secondary carnivores?
~1/1000. (not the same as the 10% rule)
82
Explain the concept of carrying capacity in
consideration of population size. Be sure to define population size, define carrying
capacity, and after doing both of these, discuss how the two are related. Next, apply these definitions and the relationship to a real-world example.
-population size is the number of individual organisms in a specific species group.
-carrying capacity is the total population size that an environment can support. This can be due to a limiting nutrient, space, or other factor.
-A population of rabbits is introduced to an island. At first, the rabbit's population size grows exponentially due to the island's lack of predators and abundance of plants to eat. However, eventually, there are too many rabbits on the island. The large population of rabbits has started to eat the island's plants faster than they can regrow. This leads the rabbit population to shrink and resemble an S-shaped growth curve. Eventually, the rabbits live on the island at an almost stable population size. This is due to factors in reproduction, not the rabbit's knowledge of a carrying capacity.
83
Choose three ways to describe a member of a biological community, and define and give an example of each.
-Foundation species: this species changes an environment in a way that allows other species to live in a habitat. Ex: Coral
-Primary producer: this is a species that is able to produce organic compounds from light or chemical energy. Ex: grass
-Keystone species: a species that has the most influence for its tropic level. Ex: snakes
-dominant species: The most abundant species. Ex: In oceans, the dominant plants are seagrass.
84
Georgyi Gause concluded that two species with exactly the same requirements cannot occupy the same niche. Discuss / explain
how morphological or behavioral differences may allow related species to coexist.
Give a total of three examples in your answer.
-realized niches: The actual set of conditions under which an organism exists. Ex: the barnacles
-resource partitioning: resources are split up by subdividing niches to avoid direct competition. Ex: anole lizards in a tree
-character displacement: differences in morphology between sympatric species. Ex: Darwin's finches
85
Compare and contrast (discuss the similarities and
differences between) energy flow and nutrient cycle, giving three examples and
discuss each process within the context of the example.
- Energy flow is not a cycle. Energy cannot be returned to lower trophic levels because the energy is non-recyclable, will be partially lost to heat, and used to maintain the body. This is different to nutrient cycles because nutrients is always traded between organisms and the environment in a cycle. This process is done without any loss of nutrients.
-The main source of energy is the sun through sunlight hitting the earth. This isn't true for the nutrient cycle because nutrients are always traded between organisms and the earth. For example, a "source" for water is the ocean. However, the water evaporated from the ocean will likely return to it after it is precipitated onto land, is drank by a organism, is respirated as a vapor, condensates into a cloud, and precipitated into the ocean. Energy cannot complete this cycle because organisms cannot return the energy back to the sun.
-One way that energy flow and the nutrient cycles are similar is the ability for both to travel through organisms as apart of their own process. For energy flow this is done by sunlight transporting energy to plants that convert the energy into organic matter which then travels up the food chain. Nutrients travel through organisms as they interact with their environment to maintain their bodies. For example, water is evaporated from the ocean, condensates into a cloud, and precipitated into a river. An animal then drinks the river water. After the animal is done using the water to maintain their body, the water is then released by respiration, sweat, waste functions, or other means. The water will then make its way back to a body of water or ocean.
86
While walking in the woods one day, you notice a dead
squirrel on the side of the trail. It has only recently died and has not yet begun the process of
decomposition. What will become of the nitrogen in the dead squirrel? Trace its flow through
the ecosystem, and explain what happens to it at each step. (Hint-hint: To earn full credit,
the answer should include the following terms: decomposers, ammonia (NH 3 ), ammonium
(NH 4 + ), nitrate (NO 3 - ), ammonification, nitrification, nitrifying bacteria, denitrifying bacteria).
First, decomposers will break down the squirrel and return the nitrogen wastes back into the soil. Ammonification then occurs by bacteria to produce Ammonia (NH4). At the same time, nitrogen-fixing bacteria are turning nitrogen gas (N2) into Ammonium (NH3). Both the Ammonia and Ammonium then go through nitrification by nitrifying bacteria into nitrate (NO3). This nitrate then goes through denitrification by denitrifying bacteria to produce nitrogen gas (N2) that is released into the atmosphere.
87
Explain three reasons why only a small portion of the solar energy that strikes Earth’s atmosphere is stored by primary producers. In your answer, be sure that at least two of the three reasons pertain to the storage of energy.
1. only 1% of the sunlight energy that makes it to Earth is captured by plants. 34 percent is reflected back into space by clouds, and 66 percent is reflected into space by the Earth itself.
2. Plants cannot store all of the energy that they capture. Plants need this energy to grow, respirate, and reproduce.
3. Even if plants could store 100% of the sunlight that they capture, they would still lose energy. This is due to the second law of thermodynamics since chemical bond or light energy is lost to heat energy (entropy).
