EXAM III Flashcards
(341 cards)
1
Q
What is an element in flux in a biogeochemical cycle?
A
An element is in flux when it is moving from one storage compartment to another.
2
Q
When does carbon show the least flux?
A
When it is deposited in ocean sediments.
3
Q
What is the main avenue by which phosphorus returns to the ocean?
A
Surface runoff.
4
Q
Why does carbon released by fossil-fuel burning cause global warming?
A
Unlike respiratory CO2, it is released faster than oceans or organisms can absorb it.
5
Q
Which is the best example of a pool where large amounts of an element can be stored for millions of years?
A
Carbon in rock and fossil fuels.
6
Q
In the equation NPP = GPP – respiration, what does GPP stand for?
A
Total carbon fixed by primary producers.
7
Q
What do nitrogen-fixing plants like soybeans convert?
A
Atmospheric nitrogen to nitrate and ammonium.
8
Q
What causes dead zones in oceans?
A
Algal blooms caused by excess phosphorus and nitrate runoff.
9
Q
Weathering is important to the input of?
A
Phosphorus
10
Q
Which aspect of the nitrogen cycle are microbes not responsible for?
A
Industrial nitrogen fixation.
11
Q
Which land ecosystem has the highest total net primary productivity?
A
Tropical rainforest.
12
Q
What is the largest pool of nitrogen in the global nitrogen cycle?
A
The atmosphere.
13
Q
How does CO2 from the atmosphere change ocean water?
A
It increases its acidity.
14
Q
What is the final destination of liquid water falling on terrestrial environments in the hydrologic cycle?
A
Ocean.
15
Q
What is the correct order of forest types from lowest to highest total NPP?
A
Boreal, temperate deciduous, tropical.
16
Q
Which is NOT a major human alteration to the global nitrogen cycle?
A
Animal waste from agriculture.
17
Q
Why is nitrogen often the limiting nutrient in ecosystems?
A
Most nitrogen is in the form of N2, which organisms cannot use.
18
Q
What causes coral bleaching?
A
High temperature and acidity cause corals’ algal symbionts to be expelled.
19
Q
What factors determine NPP values in deserts and tundra?
A
Deserts are limited by precipitation and tundra by temperature.
20
Q
What is the largest pool of water on Earth?
A
Ocean.
21
Q
What is TRUE about the global hydrologic cycle?
A
Precipitation is greater than evaporation in terrestrial ecosystems.
22
Q
What is the least likely fate of a molecule of carbon dioxide dissolved in ocean water?
A
It will be incorporated into a fossil fuel.
23
Q
The carbon cycle in ecosystems mostly follows the same paths as the movement of what?
A
Energy.
24
Q
What primarily causes global climate change?
A
Increased levels of carbon dioxide in the atmosphere.
25
What is the primary source of energy for life on Earth?
Solar radiation.
26
What is a logical path for a molecule of water starting and ending in the atmosphere?
Precipitation, infiltration, evaporation, condensation.
27
How does carbon dioxide exchange between the atmosphere and aquatic ecosystems occur?
Bidirectionally and nearly equally.
28
What provides the energy required for evapotranspiration?
The Sun.
29
Tropical terrestrial ecosystems, such as rainforests, have very high NPP. NPP declines as you move northward through temperate deciduous forests and then boreal forests. In the open ocean, NPP shows much less variation with location. These differences reflect varying land and ocean patterns based on?
Latitude
30
Which ecosystem has the lowest levels of primary productivity?
Desert scrub.
31
What does NOT significantly affect terrestrial decomposition rates?
Phosphorous content of litter.
32
What occurs when there is an excess of nutrients in aquatic environments?
This causes a spike in primary production that can actually cause die-offs of other organisms. This is often seen in aquatic environments due to run-off
Eutrophication.
33
What changes occurred in the biomes of the Aleutian archipelago due to arctic foxes?
Grassland to tundra.
34
What caused an increase in carbon dioxide pulled from the atmosphere in the Midwestern lake case study?
The decrease in the number of bass led to the increase in the number of phytoplankton.
35
What happened to the Bald Eagles' diet when otters were absent?
The eagles ate more birds than mammals and fish.
36
When a wildebeest population [A], vegetation [B], which increases fire risk.
A - Decreases B- Increases
37
What does a dam creating islands without predators lead to?
Large amounts of herbivores.
38
Why are food chains relatively short?
Energy transfers are not perfectly efficient.
39
What are biological controls?
A species introduced to help control the abundance of another species.
40
What is it called when predators respond to prey densities through population growth?
Numerical response.
41
What happened to spider populations on islands without lizards?
Spider populations became more abundant.
42
Is Drosophila sechellia's ability to tolerate vomit fruit an example of coevolution?
No, because the plant has not evolved in response.
43
A new species of insect is introduced into South America from Africa. The populations of the new insect grow, but bats keep population sizes low, and they do not have any negative effects in South America. How would this insect species be classified?
An introduced, non-invasive species.
44
What Type response is it when a predator's rate of prey consumption increases linearly with prey numbers?
Type I functional response.
45
You are part of an international panel concerned about the reduction of bay scallops in the Atlantic. The top predators in the area are shark populations, which currently are being overharvested, and the main mesopredator on bay scallops is the cownose ray. What action could the international panel take that would BEST allow them to achieve their goals?
Negotiate strict fishing regulations to reduce shark fishing and bycatch.
46
What is a 'search image' associated with?
The efficiency with which predators capture prey.
47
What is true about the interaction between sea urchins and algae?
Algae biodiversity is higher when sea urchins are present.
48
What data would indicate that predators limit vole populations?
Vole populations reach carrying capacities only when predators are removed.
49
What introduced species severely degraded Macquarie Island's biological communities?
House cats and rabbits.
50
What does the dotted line in graph a represent?
The prey isocline.
51
This graph shows the proportion of the prey population consumed by each predator depending on the density of the prey population. In a type II functional response, a predator's rate of prey consumption begins to slow down as prey density increases and then plateaus when satiation occurs. Which line on the graph indicates the proportion of the prey population consumed with this type of predator response?
(FIRST GRAPH PREDATION)
B
52
According to the Lotka-Volterra model, a predator population will decrease whenever _____.
According to the Lotka-Volterra model, a predator population will decrease whenever _____.
N < m ÷ ac [[The predator population will decrease whenever the predator death rate is higher and they are less efficient at catching prey and converting them into offspring.
53
What occurs at the joint equilibrium point?
Both predator and prey populations are stable.
54
This graph shows the proportion of the day that tadpoles remain active in the presence of a caged predator (right-hand bar for each species) or in the presence of an empty cage. Which of the following CANNOT be inferred from this graph?
(SECOND GRAPH UNDER PREDATORS)
The tree frog is larger than the leopard frog. [The graph does not provide any information about the size of adult frogs.]
55
What is an example of bottom-up control?
A population of red foxes declining while their prey remains unchanged.
56
In the context of predation, top-down control is what?
The unidirectional influence of higher trophic levels exerted upon lower ones
57
What is not typically a major component of predation models?
Migration.
58
Herbivory is a form of predation? T/F
True.
59
What is it called when an organism mimics a dangerous prey species?
Batesian mimicry.
60
What occurs during intraspecific competition?
When glad eagles compete for fish out of the same lake.
61
What occurs during interspecific competition?
When any two species compete for a limited resource.
62
Why was Synedra a better competitor than Asterionella?
It reduced the shared limiting resource to the lowest level.
63
What does Leibig's law of the minimum fail to consider?
The interaction of resources can limit growth.
64
If a plant is primarily limited by nitrogen and secondarily by phosphorus, according to Leibig's law of the minimum, Under what circumstances would adding phosphorus increase a plant's growth rate?
If nitrogen is added first to alleviate limitation.
65
What equation are mathematical models for competition based on?
Logistic population growth.
66
When do populations approach stable equilibrium?
When growth rate nears zero.
67
What are α12 and β21 in Lotka–Volterra models?
Competition coefficients.
68
What does the variable K represent in Lotka–Volterra models?
Carrying capacity.
69
What can competition coefficients be used for?
To convert between the number of individuals of one species and the number of individuals of another species
70
What do graphical models of competition tell us?
That coexistence of two competing species is most likely if intraspecific competition is stronger than interspecific competition.
71
What is the zero-growth isocline defined in terms of?
Population.
72
The resource requirements of two plant species, A and B, have been carefully studied. Researchers have determined the levels of a particular resource that will support equilibrium levels of each species. Species A needs more of this resource to maintain equilibrium than does species B. When these two species are set in competition (under conditions in which this resource is limiting)
What is likely to happen when two plant species compete for a limiting resource?
Species B will displace species A.
73
What is exploitative competition?
When one individual drives down a resource to a point where another cannot persist.
74
What is interference competition?
When two species interact directly to aggressively defend resources.
75
When long-legged ants plug the nest entrances of red harvester ants with which they compete for seeds, it is called?
Interference Competition
76
Researchers have determined that common reed damages roots of other species by secreting gallic acid. This is an example of _____ competition.
Interference
77
What is it called when organisms use chemicals to suppress competitors?
Allelopathy.
78
Scientists believe that some species of eucalyptus in Australia promote frequent fires by means of flammable oils in their leaf litter. These fires kill completing plants.
What type of competition do eucalyptus species promote through frequent fires?
Allelopathy.
79
What information is NOT needed for the Lotka–Volterra model?
The efficiency of conversion of resources to offspring.
80
What is NOT a possible outcome of the Lotka–Volterra competition model?
Both species x and y will go extinct.
81
What is the predicted outcome of competition between two species based on the graph?
(UNDER COMPETITION- PICTURE GRAPH)
Depending on initial population sizes, either species 1 or species 2 could win.
82
What is true about competition between individuals of two species?
It has a negative effect on both.
83
What is competition characterized by?
It is costly, experienced within and between species, and can limit population growth.
84
Walnut trees produce hard green fruit which contain toxic chemicals in their flesh; when the fruit falls onto the ground, it releases chemicals into the soil, killing any plants surrounding the fruit which may otherwise compete with the seedling inside.
The chemical compeition between plants is known as allelopathy.
Allelopathy is an example of what kind of competition:
The chemical competition that kills surrounding plants.
85
What is the R star value for the Harbor Seal?
700.00.
86
What is the R star value for the Canadian Lynx?
3.148.
87
What is the R star value for the Least Weasel?
61.754.
88
What is the R star value for the Hooded Skunk?
15.455.
89
Which species would win based on R star values?
b. Canadian Lynx.
90
What ectoparasites are commonly associated with plants?
Nematodes.
91
What does R0 represent in the S-I-R model of infectious disease transmission?
The ratio of the rate of new infections to the rate of recoveries.
92
Name some intracellular parasites?
Protozoa, bacteria, fungi, and helminths.
93
Assume you have one sample of eight amber snails infected by the parasitic flatworm, Leucochloridium paradoxum and one sample of uninfected amber snails. How many degrees of freedom are there?
There are 14 degrees of freedom. Adding the sizes of the two samples together, which is 16, and subtracting 2, which is the number of samples, yields 14 degrees of freedom.
94
When HIV enters a human cell, how can it hide from the body's immune system?
by living in the cell's cytoplasm
95
What happens to the number of susceptible individuals over time in the S-I-R model?
As time progresses, the number of susceptible individuals should decrease.
96
What caused the sharp increase in West Nile virus infections and deaths in the U.S. in 2012?
abundant rain that created a lot of standing water, combined with unusually warm and humid conditions
97
When the pathogenic fungus Entomorpha muscae infects yellow dung flies, the fungus changes the height at which the dung flies perch and the part of the leaf on which they perch. Researchers gathered data on the height and position of uninfected and infected dung flies. Given four yellow dung flies found at different heights and in different positions, which fly is likely NOT infected?
(LOOK AT PICTURE SLIDE)
height of 10 cm, upper surface of leaf
98
What does the parasitic flatworm Leucochloridium paradoxum do to increase its chances of completing its life cycle?
The flatworm changes the appearance of a snail's eyestalks and manipulates a snail's behavior to make the snail more conspicuous to a predatory bird in which a flatworm can reproduce.
99
How do the sizes of parasite and host populations fluctuate over time?
They alternate with one increasing while the other decreases.
100
What led to the decreasing efficiency of the Myxoma virus in controlling European rabbit populations in Australia?
selection for virus strains that did not kill their host
101
What is TRUE about parasite and host species?
A parasite typically has one or a few host species. Although a host species can carry dozens of parasite species, a parasite species infects only one or a few host species.
102
In the SIR model of infectious disease transmission, what does (S×I×b) represent?
rate of infection between susceptible and infected individuals
103
What happens when a mouse consumes the parasitic protist Toxoplasma gondii?
If the mouse is consumed by a bobcat, the parasite is able to complete its life cycle.
104
What occurs when a host species first develops immunity to a parasite after an initial infection?
A higher proportion of the host population develops immunity.
105
Where do ectoparasites live and give examples?
Ectoparasites live on the body. Examples: such as lice, ticks, and fleas
106
Where do endoparasites live and give examples?
Endoparasites live inside the body and can be intra or intercellular. Examples: such as tapeworms, roundworms, and flukes
107
Define Infection resistance.
the ability of a host to prevent an infection from occurring
108
Define Infection tolerance.
the ability of a host to minimize the harm once an infection has occurred
109
Define Parasite load.
the number of parasites of a given species that an individual host can harbor
110
Define Reservoir species.
species that can carry a parasite but do not succumb to the disease that the parasite causes in other species
111
Define Vector.
an organism that a parasite uses to disperse from one host to another
112
Define Vertical transmission.
when a parasite is transmitted from a parent to its offspring
113
Define Horizontal transmission.
when a parasite moves between individuals other than parents and their offspring
114
What is a Susceptible-infected-resistant (S-I-R) model?
the simplest model of infectious disease transmission that incorporates immunity
115
Explain the basic S-I-R model.
All individuals in a population are initially susceptible. When the infection is introduced at the beginning of the time period, there is an initial rapid growth in the number of infected individuals. As some infected individuals recover and become resistant, there are fewer susceptible individuals left to infect, so the number of infected individuals declines.
116
Define Characteristics of Facultative Brood Parasites.
Care for their own nest and also lay eggs in other bird’s clutches.
117
Define Characteristics of Obligate Brood Parasites.
Do not provide care for their own young. Exclusive parasite. Approximately 1% of birds.
118
Compare Ecto/Endo parasites regarding Exposure to natural enemies.
Ectoparasites - High
Endoparasites - Low
119
Compare Ecto/Endo parasites regarding Exposure to external environment.
Ectoparasites - High
Endoparasites - Low
120
Compare Ecto/Endo parasites regarding Difficulty of movement to and from host.
Ectoparasites - Low
Endoparasites - High
121
Compare Ecto/Endo parasites regarding Exposure to host's immune system.
Ectoparasites - Low
Endoparasites - High
122
Compare Ecto/Endo parasites regarding Ease of feeding on host.
Ectoparasites - Low
Endoparasites - High
123
Explain Parasites.
Live on host tissue and reduce host fitness, but do not generally kill the host. They depend on the host thus, thus killing the host could kill them.
124
Explain Parasitoids.
Consume the host (generally insects). Usually are lethal. Offspring generally kill the host.
125
Explain Parasitic Relationships.
when parasites benefit (+) at the expense of their host (-). The parasite relies on the host for resources (such as nutrients or a place to live), often causing harm to the host in the process.
The host is typically harmed by the parasite, which can lead to disease, reduced fitness, or even death in some cases.
126
Describe viruses' impact on host species.
can weaken or kill the host, often through vector transmission. Examples: such as Blue Tongue and Rift Valley Fever
127
Describe the impact of Protozoan on host species.
Cause diseases like Chagas Disease, which affects the heart and digestive system of the host. Example: Trypanosoma cruzi
128
Describe the impact of Prion on host species.
Affect the nervous system, often leading to the death of the host. Example: Those causing Chronic Wasting Disease in deer
129
Describe the impact of Bacteria on host species.
Cause diseases like tuberculosis, affecting a wide range of species. Example: Mycobacterium tuberculosis
130
Describe the impact of Fungi on host species.
that infect amphibians and cause population declines. Examples: Chytrid fungus
131
What determines parasite and host dynamics?
the probability that the parasite can infect the host.
132
Define Host availability.
The more hosts available, the more likely it is that the parasite will find a host.
133
Define Parasite virulence.
How harmful the parasite is to the host can affect the likelihood of infection.
134
Define Host defenses.
Hosts with strong immune systems or behavioral defenses (like grooming) are less likely to become infected.
135
Why are there fluctuations of host and parasite populations?
when a parasite population grows too large, it can significantly reduce the host population, which in turn can cause a decline in the parasite population due to a lack of hosts.
Once the parasite population decreases, the host population can rebound, leading to another increase in the parasite population. EXAMPLE: weevils parasitized by wasps experiment: This experiment showed that over 40 generations, the populations of wasps and weevils fluctuated in cycles, with peaks and troughs in both populations.
136
What are Parasites' offensive strategies to increase their chances of transmission and infection?
Host detection & host behavior alteration
137
Define Host detection.
Parasites must be able to find suitable hosts, which can involve complex sensory mechanisms.
138
Define Host behavior alteration.
Parasites may alter the behavior of their hosts to increase transmission. Example: Toxoplasma alters the behavior of mice, making them less afraid of predators.
139
What are the hosts' evolved defensive strategies against parasitic infection?
Immune responses, Behavioral defenses and Evolution of resistance
140
Define Immune responses.
Hosts develop immune mechanisms (like antibodies) to fight off infections.
141
Define Behavioral defenses.
Hosts may engage in behaviors such as grooming, which reduces parasite load.
142
Define Evolution of resistance.
In some cases, hosts evolve genetic resistance to certain types of parasites.
143
What is the ongoing 'arms race' between parasite offensive strategies and host defensive strategies?
leads to continuous evolutionary pressures on both sides.
144
What are the two types of mutualism?
Faculative & Obligate
145
Define Facultative mutualism and give an example.
a partner does not need to engage in a mutualistic relationship to be successful. Example: Cleaner wrasse cleans the mouths and gills of various fish species.
146
Define Obligate mutualism and give an example.
is the opposite. The partner MUST engage in the relationship. Example: The yucca plant depends on pollination by the yucca moth. After pollination, they feed on the yucca seeds. Some moths “cheat” and dont pollinate.
147
Explain Tricky Flowers.
A common tactic among orchids is to mimic female thynnine wasps. They secrete chemical cues and visual cues to trigger mating response.
When the male attempts to mate with the flower, the labellum of the flower swings over, flips the male wasp upside down and directly onto the stigma, right where the pollen load is needed for pollination.
148
What happens when ants are removed from Acacia?
Acacia are consumed by herbivores. Survival is dramatically reduced due to a lack of ability to defend against herbivory.
149
Give an example of mutualisms affecting species distributions.
Cleaner wrasse remove parasites from fish in coral reefs. Without wrasse, the abundance and diversity of fish significantly decreased.
150
Explain the saying 'elephants are scared of ants.'
Ants can swarm inside and bite elephant trunks, causing elephants to avoid acacia trees defended by ants.
151
Define Mutualism.
Interaction between individuals of different species that benefits both partners.
152
Define Obligate mutualism.
is when one or both species must engage in the mutualistic relationship for survival.
153
Define Facultative mutualism.
When the relationship benefits both species, but neither needs the other to survive.
154
Define Bee pollination form.
Bees are diurnal, have good vision, and are drawn to colorful flowers.
155
Define Bird pollination form.
Birds have excellent vision and are attracted to long-tubed flowers.
156
Define Bat pollination form.
Bats are nocturnal and hover, with bright-colored flowers opening at night.
157
Define Fly pollination form.
Flies are attracted to the scent of decomposing flesh, and flowers pollinated by flies often have dark colors and a foul odor.
158
Why would acacia trees that no longer experience herbivory provide smaller rewards for mutualistic ants?
Acacia trees provide rewards (nectar, Beltian bodies) to ants for defense against herbivores. If large herbivores are no longer present, the trees experience less herbivory pressure and, in turn, have less need to "pay" ants for protection.
Without the threat from herbivores, the tree may reduce the rewards to the ants since the service of defense is less needed.
159
How might an increase in soil nutrients alter a mutualism between plants and mycorrhizal fungi?
Increased soil nutrients would reduce the reliance of plants on mycorrhizal fungi for nutrients like phosphorus.
Tthe mutualism may become less equitable because the plant would not need the fungus as much for nutrient acquisition, and the fungus may not receive as much carbohydrate (glucose) from the plant. This could shift the dynamic toward a less mutualistic or more exploitative relationship.
160
Why would increasing the diversity of mycorrhizal fungi lead to greater plant productivity?
Greater diversity of mycorrhizal fungi increases the range of nutrients and benefits available to plants.
Different fungal species may specialize in accessing different nutrients, so a more diverse fungal community can help plants access a wider variety of nutrients, potentially leading to greater overall plant productivity. This increased access to nutrients can enhance plant growth and health.
161
If cleaner wrasse consume both parasites and scales from larger fish, what determines whether the interaction is mutualism or parasitism?
The interaction would be classified as mutualism if the cleaner wrasse primarily help the larger fish by removing harmful parasites.
162
Give an example of how a mutualism between two species could alter the diversity in an ecosystem.
Cleaner wrasse help remove parasites from fish in coral reefs. When cleaner wrasse are removed, the abundance and diversity of fish significantly decreased.
163
Which of the following describes the relationship between a grass and mycorrhizae?
Mutualism
164
What is the co-evolutionary arms race between rough-skinned newts and common garter snakes?
Rough-skinned newts evolve to produce high levels of the toxin TTX, while garter snakes evolve high resistance to this toxin.
165
Which of the following is NOT an example of coevolution?
American bullfrogs can jump up to twenty feet in the air to catch different prey species.
166
What describes the relationship between dogs and grass when fecal matter helps fertilize the grass?
Commensalism
167
What are individual interactions with mates, offspring, and other relatives called?
Social behaviors
168
Why is global warming affecting the social behaviors of many animals?
Changes to seasonal weather patterns affect the timing and routes of annual migrations.
169
When two hyenas hunt and kill a zebra together and share in eating it, what is this social behavior called?
cooperation; where the donor experiences increased fitness and the recipient experiences increased fitness from the interaction.
170
When should altruism be favored by natural selection?
When the inclusive fitness from altruistic behaviors exceeds the inclusive fitness from selfish behaviors.
171
Which potential reason for making alarm calls is most likely to be FALSE?
They enhance the dilution effect.
172
An individual would gain higher inclusive fitness by helping his brother mate than by himself mating if his what?
indirect fitness benefit is more than two times his direct fitness cost.
173
Eusociality evolves when the coefficient of relatedness is high or when what is low?
the cost of forgoing reproduction.
174
What scenario illustrates the dilution effect?
An individual sardine has a lower predation risk while swimming in a large group.
175
What C:B ratio for altruistic behavior must be exceeded for natural selection to favor the evolution of altruism between donor individuals and their half siblings?
0.25
176
What sex-determination system appears to favor the evolution of eusocial behavior?
haplodiploid; providing large indirect fitness effects when diploid workers forgo breeding to help their diploid siblings.
177
Why do many people consider licensed hunting of deer an important tool for managing wild deer populations?
Hunting deer reduces disease outbreaks and competition for food.
178
Explain an Example where Mutualisms can aid in defense with Ants & Acacia
Ants provide: Defense against herbivores, Removal of weeds or other plants that create too much shade
Acacia provide: Thorns to house ants, Extrafloral nectaries, Beltian bodies for oils and protein
179
Allelopathy is an example of what kind of competition:
Interference Competition
180
What is primary production?
Primary production is the rate at which solar energy is captured and converted into chemical bonds by photosynthesis.
181
How is primary production calculated?
By using the equation: NPP (net primary productivity) = GPP (gross primary productivity) - Respiration (by the producer)
182
What factors can affect the amount of primary production in an ecosystem?
Moisture and temperature factors that affect primary production. However, the presence of limiting nutrients like nitrogen and phosphorus can also affect primary production.
183
Define Sources.
Sources are pools of nutrients that release more than they absorb.
184
Define Sink.
Sinks are pools of nutrients that absorb more than they release.
185
Summarize the Carbon Cycle’s sources of each nutrient.
The atmosphere and the soil (as fossil fuels) are major reservoirs of carbon. Organisms can be sources of carbon (trees or organisms when they respire or die) as well as the burning of fossil fuels or forest fires.
186
Summarize the Nitrogen Cycle’s sources of each nutrient.
The nitrogen cycle has a lot of turnover. The atmosphere is a large nitrogen reservoir as well as the soil. Organisms through death/decomposition as well as our own fertilization of fields can be sources of nitrogen.
187
Summarize the Phosphorus Cycle’s sources of each nutrient.
The phosphorus cycle is an imperfect cycle because phosphate exists in a solid state. Phosphates move via rain or snow melt. They are used by plants and animals and are released back into the ecosystem when plants and animals die. Humans are also a source of phosphates with fertilizers and some detergents.
188
Summarize the Hydrologic Cycle’s sources of each nutrient.
The water cycle or hydrologic cycle is a perfect cycle. The ocean is a water sink. Water evaporates from the ocean, condenses, and precipitates. It infiltrates (or soaks into the soil) becoming groundwater or streams and rivers. These ultimately end up back in the ocean.
189
What is a dead zone? How is it created?
Dead zones are large areas of low to no dissolved oxygen in the water. This is due to agricultural runoff of fertilizers. This causes algal blooms which can lead to a large amount of decomposition.
Decomposers use a large amount of oxygen, leaving little oxygen for other ocean organisms. This leads to hypoxic (low-oxygen) conditions — creating a dead zone where most marine life cannot survive.These organisms die which leads to more food for decomposers.
190
Why is the pH of the ocean dropping?
Carbon dioxide from burning fossil fuels mixes with ocean water, lowering the pH of the water by forming carbonic acid.
191
How will pH dropping affect ocean life?
Carbonic acid reduces the amount of free carbonate ions, which are used to form the exoskeletons and shells of marine invertebrates, leading to eroded or weak exoskeletons.
192
Define primary production.
Primary production is the rate at which solar or chemical energy is captured and converted into chemical bonds by photosynthesis or chemosynthesis.
193
Differentiate between Net and Gross Primary Production.
Gross Primary Production (GPP) is the total amount of biomass produced by autotrophs in an ecosystem. Net Primary Production (NPP) is the amount of biomass remaining after autotrophs use some of that energy for respiration.
194
How is Net Primary Production calculated?
NPP = GPP - R
195
Explain why Net Primary Production may differ between ecosystems.
Moisture and temperature, nutrient availability (e.g., nitrogen and phosphorus), light penetration in aquatic systems, and type of ecosystem affect Net Primary Production.
196
Define Primary Production.
Energy capture and biomass generation by autotrophs (plants, algae, etc.) using sunlight or chemical energy.
197
Define Secondary Production.
Biomass production by heterotrophs (consumers) from consuming primary producers or other consumers.
198
Define perfect cycles.
Nutrients continuously cycle with no major losses. Example: carbon, nitrogen, water.
199
Define imperfect cycles.
Nutrients can be lost for long periods, typically tied up in rocks or sediments. Example: phosphorus.
200
Explain how ocean acidification occurs.
Human activities (like burning fossil fuels) release CO₂ into the atmosphere. Some of this CO₂ dissolves in ocean water, forming carbonic acid, which lowers ocean pH.
201
What are some Sources in Carbon Cycle.
CO₂ in the atmosphere, respiration, fossil fuel burning.
202
What are some Sinks in Carbon Cycle.
Soil (as organic matter), peat, fossil fuels, and carbonate rocks. Plants 'fix' carbon during photosynthesis to form sugars.
203
Define Source in Nitrogen Cycle.
Atmospheric nitrogen (N₂) — it’s a perfect cycle.
204
Define Sink in Nitrogen Cycle.
Although nitrogen cycles through many forms, it doesn't have a long-term storage pool like rocks or sediments. Only nitrogen fixers can directly use atmospheric N₂, converting it into ammonia (NH₃). Once fixed, nitrogen becomes available to most organisms.
205
The Hydrologic cycle is also called the what?
The water cycle.
206
Describe the water content of the Hydrologic Cycle.
~Over 71% of the Earth’s surface is covered by water:
~Oceans contain 97% of the water.
~Polar ice caps and glaciers contain 2%.
~Freshwater in lakes, streams, and ground water make up less than 1%.
207
What is the 1st Law of Thermodynamics?
Energy cannot be created or destroyed (can be converted from one form to another).
208
What is the 2nd Law of Thermodynamics?
As energy is transferred or transformed, more and more of it is wasted (entropy).
This tells us how much energy is spread out in a closed system (energy quality)
209
Define the Law of Conservation of Mass.
Mass is neither created nor destroyed within chemical reactions.
210
Define Reducer-decomposers.
Break down initial material into smaller or more digestible components for fungi and bacteria.
211
What are the two classes of decomposers?
Reducer decomposers & Ultimate decomposers.
212
Define Actual evapotranspiration (AET).
The quantity of water that is removed from a surface due to the processes of evaporation and transpiration.
213
Explain why food chains are relatively short within a food web.
Food chains are short because of inefficient energy transfer between trophic levels. Only about 10% of energy from one level is passed on to the next. This low energy transfer limits the number of possible links — if you go too many levels up, there’s simply not enough energy left to support organisms.
214
Define Photosynthetic Efficiency.
Measures how efficiently plants convert sunlight (PAR: photosynthetically active radiation) into biomass.
215
Define Consumption Efficiency.
The percentage of available biomass in one trophic level that is actually consumed by the next level.
216
Define Assimilation Efficiency.
Measures how much of what is consumed is actually assimilated (digested and absorbed), excluding waste.
217
Define Growth Efficiency.
Measures how much assimilated energy is used for growth or reproduction, rather than lost to respiration.
218
Define Ecological Efficiency.
The overall efficiency of energy transfer from one trophic level to the next.
219
How is Photosynthetic Efficiency calculated?
Net production / PAR (PAR: photosynthetically active radiation).
220
How is Consumption Efficiency calculated?
Biomass consumed / Biomass available from previous level.
221
How is Assimilation Efficiency calculated?
Assimilated energy / ingested energy.
222
How is Growth Efficiency calculated?
Net production / assimilation.
223
How is Ecological Efficiency calculated?
NP at current level / NP at previous level.
224
Give an example of how a consumer can impact the diversity in its community.
Littorina littorea (a snail) affects algal diversity in tide pools. In experiments where the snails were excluded, the algal community composition changed.
This shows that snails directly affect lower trophic levels, shaping which species thrive — they control community diversity through their feeding preferences.
225
Define trophic cascade and give an example.
An indirect effect initiated by a predator that ripples down through the lower trophic levels.Can be density-mediated (due to changes in population size) or trait-mediated (due to behavioral or physical trait changes).
Example: When a predator reduces herbivore density, allowing plant populations to increase — that's a top-down trophic cascade.
226
Define keystone species and give an example.
Has a large impact on community structure, despite low biomass. They increase species coexistence by preventing competitive exclusion.
Example: In Robert Paine’s experiment, removing the Pisaster sea star from the rocky intertidal zone reduced species diversity from 15 to 5. Pisaster was preventing one species from dominating, thus maintaining diversity.
227
Define Dominant Species.
Dominant species have a large impact on their community structure, due to their high biomass.
228
Differentiate between a keystone species and a dominant species.
Keystone
~ low biomass, high impact
~ maintains diversity by limiting dominant species
Dominant Species
~High biomass, high impact
~ Influences ecosystem through abundance
229
Define Bottom-up control.
When the abundances of trophic groups in nature are determined by the amount of energy available from the producers in a community.
230
Define Top-down control.
When the abundance of trophic groups is determined by the existence of predators at the top of the food web.
231
Name the benefits of keystone species increasing local diversity.
~ more productive and they produce more biomass (the total mass of all organisms).
~more stable in their productivity.
~better able to withstand and recover from environmental stresses.
~more resistant to invasive species, organisms that become established outside their native range.
232
Define Trait-mediated indirect effect.
An indirect effect caused by changes in the traits of an intermediate species.
233
Define Density-mediated indirect effect.
An indirect effect caused by changes in the density of an intermediate species.
234
Define The energetic hypothesis.
Suggests that length of each link of the food chain is limited by inefficient energy transfer.
235
Why would the predator of small prey cycle faster than the predators of large prey?
Smaller prey reproduce faster, and their populations fluctuate more rapidly.
Predators that rely on fast-reproducing prey (like insects or small rodents) also cycle faster, because their food availability changes quickly.
Predators of large prey (which have slower reproduction rates) cycle more slowly due to delayed resource recovery.
236
What are 4 ways that prey have evolved to escape predation?
Spines or hairs, camouflage, chemical defenses, and mimicry.
237
What are 4 ways that plants have evolved to escape herbivores?
Producing toxins, thicker leaves, volatile chemicals, and vibration detection.
238
Define top-down controls. Give an example.
A higher trophic level influences the community structure of a lower trophic level through predation. Example: Foxes vs. Hare.
239
Define bottom-up controls. Give an example.
Unidirectional influence from lower to higher trophic levels, driven by their diet rather than predation. Example: Foxes vs. Voles.
240
Demonstrate how predators and herbivores can limit the abundance of populations.
Predators and herbivores affect abundance by consuming individuals, which directly reduces population size and prevents overpopulation.
Examples : Snail exclusion experiments: When herbivorous snails are removed, algal populations change dramatically.
Fox removal: When predators are removed, prey populations like hares and voles increase.
241
Explain how populations of consumers and consumed can fluctuate in regular cycles.
Consumer-prey cycles are when predator and prey populations influence each other’s numbers over time.
Example: Huffaker's mite study where predator and prey populations rise and fall in repeating cycles. These cycles often occur due to time lags in population growth and resource availability.
242
Explain how predation and herbivory favor the evolution of defenses.
Constant pressure from being eaten selects for traits in both prey and plants that increase survival.
This leads to:
~Morphological defenses (e.g., spines, thicker shells/leaves)
~Behavioral changes (e.g., herding, fleeing)
~Chemical defenses (e.g., toxins or volatile compounds)
These adaptations increase over time as the individuals with the best defenses survive and reproduce.
243
Give examples of defenses of plants and animals to predation and herbivory.
~Animal Defenses:
~Hiding, herding/schooling
~Camouflage or mimicry (e.g., poison dart frogs, Müllerian mimicry)
~Shell thickening in mussels/snails when exposed to predator cues
244
Explain how chemical cues could alter a prey species behavior or allocation of resources.
~ chemical cues (even without physical presence of predators) trigger behavioral and physiological responses, shifting energy toward defense rather than growth or reproduction.
Examples:
~Mussels exposed to water from green crabs allocated more energy to making thicker shells.
~Snails exposed to crab scent altered their feeding behavior and also increased shell thickness.
245
Define Numerical Response.
As prey population increases, the predator increases its numbers through an increase in the birth rate or through immigration.
246
Define Functional Response.
Rates of predation can increase when prey are more abundant.
247
What are the 4 main components of predation?
Search, capture, handling, and digestion.
248
What is a type 1 functional response curve?
Filter Feeder Curve.
249
What is a type 2 functional response curve?
General Invertebrate Curve.
250
What is a Type 3 functional response curve?
Learning Predator curve.
251
What functional response curve is based on the assumption that a predator may encounter a prey within a fixed time?
Type 1.
252
What functional response curve is ideal for small prey densities found predominately with passive predators?
Type 1.
253
What functional response curve is a decrease in the prey present, prey eaten slowly?
Type 2.
254
What functional response curve is the most common when search rate is considered a constant?
Type 2.
255
What functional response curve is ideal for small prey densities found predominately with passive predators?
Type 1
256
What functional response curve is a decrease in the prey present, prey eaten slowly?
Type 2
257
What functional response curve is most complex because it considers learned behaviors?
Type 3
258
Define Herbivory (+/- interaction)
a predator-prey interaction, refers to an interaction in which an herbivore eats parts of a plant or alga.
259
What are talking trees?
Plants produce anti-herbivore toxins, thicker leaves, or volatiles to communicate about herbivores.
260
What adaptations do prey display to avoid being eaten?
Hiding, fleeing, and forming herds or schools. Animals have morphological and physiological defenses.
261
Define Batesian mimicry.
A palatable or harmless species mimics an unpalatable or harmful model.
262
Define Mullerian mimicry.
Two or more unpalatable or dangerous species resemble each other.
263
Define interference competition.
Direct competition where individuals physically prevent or limit access to a resource.
## Footnote
Example: Elephant seals fighting for mates, Ants burying rival nests.
264
Define exploitation competition.
Indirect competition where one organism depletes resources, making them unavailable for others.
## Footnote
Examples: Multiple animals using a watering hole & Limited nesting sites.
265
Define apparent competition.
Indirect interaction via a shared predator; one prey's presence increases predator pressure on another.
Examples: Invasive plant provides cover for predator that targets native species.
266
Describe predicting the winner of competion using a population growth isocline.
~Isoclines represent where species have zero growth (dN/dt = 0).
Species 1 wins if its isocline lies above that of species 2.
Species 2 wins if its isocline lies above species 1.
If the isoclines cross, outcome depends on:
Unstable equilibrium – either species may win (depends on starting population)
Stable equilibrium – both species can coexist (rare)
(Tip from notes: The isocline that lies on top typically indicates the winning species.)
267
Explain how resource-based competition models differ from Lotka-Volterra Competition Models.
Lotka- Describes outcomes of competition (win/lose or coexist) using competition coefficients (α), Doesn’t identify which resource is limiting, More theoretical and general
~ Resource-Based-Explains why species win/lose by looking at actual resource use and availability, Focuses on specific resource limitation, More mechanistic and tied to real-world resources
268
Describe Liebig's Law of the Minimum and how it relates to competition.
~Proposed by Liebig (1840).
States: Population size is constrained by the resource that is in shortest supply.
This means competition will be most intense for that limiting resource.
Directly supports resource-based competition modeling—whoever uses the scarce resource most efficiently wins.
269
Describe the R* Rule. Use R* calculations to predict the winner of the competition.
R* = minimum level of a resource a species needs to balance growth and mortality (i.e., dN/dt = 0)
Species with the lowest R* for a given resource will outcompete others because it can survive on less.
R* = (K × m) / r
K = half-saturation constant
m = mortality rate
r = intrinsic rate of increase
270
Define cooperation.
A behavior that has a beneficial influence on a recipient. It can sometimes appear selfless, but cooperative behaviors can provide direct or indirect fitness benefits to the actor.
For example, helping kin or increasing one's standing in a group.
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How is cooperation enforced?
Punishment: If the cost of punishment outweighs the benefits of defecting, cooperation becomes an evolutionarily stable strategy (ESS).
Example: In meerkats, infanticide and eviction are used to enforce cooperation. Pregnant females may evict subordinates, who then return and help, increasing cooperation.
~Cleaner wrasse fish are punished when they cheat by biting their clients instead of cleaning them. The clients may leave or chase them, discouraging future cheating.
272
Why do organisms cooperate?
Kin Selection, Group Augmentation, By-product Benefits, Reciprocity.
273
Define By-product Benefits.
Cooperative acts benefit both parties as a side effect.
Example: Lance-tailed manakin beta males help with courtship displays and gain future mating skills
274
Define Kin Selection.
Helping relatives increases indirect fitness. (helping related individuals reproduce helps pass on shared genes).
275
Define Group Augmentation.
Being in a larger group improves survival (meerkats benefit from predator detection, better territories, and care for young).
276
Cooperation among non-kin can evolve if what?
Cheats can be recognized and punished, There are repeated interactions, The benefit outweighs the cost
277
Explain Hamilton’s rule.
When altruism can evolve. Altruism is favored if the benefit to the recipient (weighted by relatedness) exceeds the cost to the altruist. This is central to kin selection, where helping relatives can still promote gene transmission.
278
What are the 3 conflicts in cooperation and conflict?
Sexual, parental, and parent-offspring.
279
Explain Parental Investment Conflict.
Investment helps current offspring but may reduce future reproductive success.
Example: Side-blotched lizards improve future fecundity if eggs are removed surgically.
280
Explain Instances of Parent-Offspring Conflict.
Offspring want more than parents are willing to give.
Nestlings beg intensely, especially in species with extra-pair copulations (EPC).
Canary chicks that begged more ended up with lower mass — begging is costly.
281
Explain Sexual Conflict between parents.
Each parent may try to reduce their own workload.
Example: In roseate spoonbills, removing one parent leads the other to increase care.
282
What are the types of social and interspecific relationships?
Amensalism, Commensalism, Altruism, Cooperative Breeding, Reciprocity, Group Augmentation.
283
Define Amensalism.
One organism is harmed, the other is unaffected.
284
Define Commensalism.
One organism benefits, the other is unaffected.
285
Define Altruism.
One benefits, the other is not harmed, often benefiting indirect fitness.
286
Define Cooperative Breeding.
Seen in birds like the Greater Ani, where multiple individuals lay eggs in the same nest.
287
Define Reciprocity.
Exchange of favors over time.
288
Define Group Augmentation.
Helping behavior to support larger, stronger groups.
289
What is an example of grime and punishment?
The cleaner wrasse normally provides a service (cleaning other fish), but sometimes they cheat. Instead of cleaning the clients they take a bite out of them. This is not good for the client and they often punish wrasse by Leaving, Chasing them
290
Define The Altruism Paradox.
The belief or practice of disinterested and selfless concern for the wellbeing of others.
291
What did Darwin call Altruism?
A special difficulty which first appeared to me insuperable.
292
Define Coefficient of relatedness.
Probability that an allele in one individual is present in another due to a recent common ancestor.
293
If you can earn benefits without cooperating, why do cooperative behaviors evolve?
Hidden benefits, By-product benefits, Group augmentation, and Kin selection.
294
What is an example of By-product benefit in hunting?
Cooperative hunting can be evolutionarily stable strategy (ESS). Lions hunt more efficiently in pairs. However, how equitable are such partnerships? Hunting costs 1 energy unit.When both work equally the prey is worth 10. When one works more the prey is worth 4. Your cost minus your benefit will result in your ultimate payoff.
295
What is the point of group augmentation in meerkats?
Your benefits may come from a large group size. Larger groups fare better: Predator alerts, High quality territory, Forage more. Young meerkats need protection. Subordinates feed and protect them while more dominant individuals forage
296
Define Enforcement.
If the cost of punishment outweighs the benefits of defecting, cooperation is enforced.
297
What can be a powerful method to enforce cooperation?
Punishment.
298
Why does altruism exist?
Total cooperation among organisms benefits them more than any other scenario.
299
What is Hamilton's rule (math)?
rB > C, altruism will increase if the benefit to the recipient is greater than the cost to the actor. (An individual will value someone to the degree that they are related.)
300
What is Direct fitness in altruism?
Reproductive success due to actions of self without help from others.
301
What is Indirect fitness in altruism?
Additional reproductive success of relatives due to an individual's actions.
302
What is Inclusive fitness in altruism?
Direct fitness plus indirect fitness.
303
What is Kin selection in altruism?
Spread of alleles that increase indirect fitness.
304
How does an individual recognize kin?
Kin recognition involves a level of chance.Cost must outweigh the benefit. Coefficient of relatedness must be high enough that there is a greater likelihood of passing on that gene than not.
305
What is Kin recognition green beards?
Recognition alleles to assess relatedness would have to create the behavior of: Signal. Ability to recognize the signal. Cooperation among signal bearers.
306
What is a “green beard”?
A 'green-beard' gene is defined as a gene that causes a phenotypic effect, allows the bearer of this feature to recognize it in other individuals, and causes the bearer to behave differently towards other individuals depending on whether or not they possess the feature."
307
What is Environmental Cues for Kin Discrimination: Rule 1?
Treat anyone in my home as kin.
308
What is Environmental Cues for Kin Discrimination: Rule 2?
Kin are those that you grow up with.
309
Explain coevolution.
the process of reciprocal evolutionary change between ecologically intimate species, and it’s driven by natural selection. When two species interact in ways that affect each other’s fitness, traits in one species can act as a selective pressure on the other — and vice versa.
Example: Newts evolved extremely toxic tetrodotoxin (TTX) to deter predators. In response, garter snakes evolved resistance to this toxin.This is a classic case of reciprocal natural selection, also known as a coevolutionary arms race.
310
Give an example of reciprocal natural selection, also known as a coevolutionary arms race.
Newts evolved extremely toxic tetrodotoxin (TTX) to deter predators. In response, garter snakes evolved resistance to this toxin.
311
Explain the process of reciprocal selection in geographic mosaic coevolution.
when two species exert selective pressures on each other. According to the Geographic Mosaic Theory of Coevolution (John Thompson, 2005), this reciprocal selection isn't uniform across a species' range. Instead, it varies geographically. Species interact in multiple populations, leading to a mosaic of Hostposts & Coldspots.
312
Define Hotspots.
Areas where strong reciprocal selection is occurring. Locations where coevolution is intense — both species are adapting rapidly in response to one another.
313
Define Coldspots.
Areas with little or no coevolution happening.Locations where there is little or no reciprocal selection — species interactions are weak or absent.
314
Explain why rough-skinned newts have extremely toxic venom.
Aposematic coloration. Rough skinned newts produce TTX (tetrodotoxin). TTX is a potent neurotoxin that can kill mice and other larger mammals in seconds.
315
What are the types of species interactions?
Mutualism, Predation, Herbivory, Parasitism, Deceptive Pollination, Commensalism.
316
Is Mutualism negative, positive? and what are the neutral effects on each other's fitness.
Positive/Positive
Both species benefit from the interaction.
Example: pollination, seed dispersal, nutrient exchange between fungi and plants.
317
Is Predation negative, positive? and what are the neutral effects on each other's fitness.
Negative/Positive
One species (the predator) benefits, while the other (the prey) is harmed.
Example: animals ingest other animals; prey evolve toxins, predators evolve resistance.
318
Is Herbivory negative, positive? and what are the neutral effects on each other's fitness.
Negative/Positive
An herbivore benefits by feeding on a plant, which is harmed.
Example: plants evolve toxins or thorns; herbivores evolve detoxification or feeding strategies.
319
Is Parasitism negative, positive? and what are the neutral effects on each other's fitness.
Negative/Positive
The parasite benefits by living in or on a host, which is harmed.
Example: parasites may manipulate host behavior; hosts evolve immune defenses.
320
Is Deceptive Pollination negative, positive? and what are the neutral effects on each other's fitness
Negative/Positive
The plant benefits by tricking a pollinator, which gets no reward.
Example: flowers mimic appearance or pheromones of female insects to attract males.
321
Is Commensalism negative, positive? and what are the neutral effects on each other's fitness.
Neutral/Positive
One species benefits, while the other is unaffected.
Example: remora fish attach to larger fish and feed on leftovers.
322
Explain how there may be hotspots and coldspots of coevolution across a species range.
According to the Geographic Mosaic Theory, coevolution varies across different geographic areas due to differences in Interaction intensity, Environmental conditions, and Genetic variation. This lead to cold and hot spots.
Hotspots: Locations where coevolution is intense — both species are adapting rapidly in response to one another.
Coldspots: Locations where there is little or no reciprocal selection — species interactions are weak or absent.
323
Define Co-evolution.
A process of reciprocal evolutionary change between ecologically intimate species driven by natural selection.
324
Where do coevolution adaptations arise from?
the same mechanisms that give rise to the other adaptations.
The first requirement for the evolution of an adaptation, of course, is that heritable variation must be present in the traits relevant to ecological interactions of species.
325
What type of predator are garter snakes?
Generalist predators, but often consume rough-skinned newts with no adverse side-effects.
326
Coevolution arises through what?
Reciprocal selection.
327
Explain the geographic mosaic theory of coevolution.
John Thompson wrote about in 2005. Species are involved in many intimate interactions across their range. This leads to variation in evolutionary forces and variation in coevolution. Hotspots vs. coldspots for coevolution.
328
Coevolutionary theory is based on what three assumptions?
1. Herbivore activity is harmful to most plants.
2. Plants evolve defenses that deter herbivores.
3. Herbivore feeding activities.
329
Define Induced defenses.
Many organisms will only mount defenses (e.g., armor themselves) when negessary. Entirely new compounds produced after an attack Called induced defenses.
330
Define constitutive defenses.
Plants usually produce a certain quantity of a chemical defense, a constant part of their arsenal.
331
What is an example of plants evolving defenses?
The production of alkaloids like caffeine and theobromine. These chemicals can paralyze or kill insects that feed on the plants.
Additionally, cardiac glycosides found in milkweeds can affect the heart and even cause vomiting or death in animals that consume them. These are all chemical defenses that evolved to deter herbivores and protect the plant.
332
What does constitutive mean in the context of plant defenses?
Constitutive refers to the chemical defenses that plants usually produce in a certain quantity as a constant part of their arsenal.
333
Define R*
rule R* is the level of the resource needed to balance mortality.
334
Define Liebig’s (1840) Law of the Minimum
Under steady state conditions, the population size of a species is constrained by whatever resource is in shortest supply.
335
Define apparent competition and give example
two prey species compete for survival through a shared predator. An example of this would be between the two plant species Brassica nigra and Nassella pulchra .
Herbivorous mammals would be the shared predator in this case. These mammals seek shelter in the Brassica nigra and forage in the surroundings. The mammals help the invasive plant by eating the competitor (native plant) which allows more resources to be allocated to the invasive plant. This is a form of INDIRECT competition
336
What is a carbon source? What is a carbon sink? Provide an Example of both.
A carbon source refers to when more carbon is being released than there is being absorbed. A carbon sink, on the
other hand, is when there is more carbon being absorbed than there is being released. Burning fossil fuels would be an
example of a carbon source. Rainforest would be an example of a carbon sink.
337
Robert Payne - What happened when the sea stars were removed? (in terms of biodiversity)
there was a decrease in biodiversity. The sea stars are a keystone species and helped regulate the community by reducing the possibility of competitive exclusion by other species
338
Co-evolutionary arms race - What two things need to occur in order for this relationship to continue between two organisms?
Host adapts mechanism, parasite adapts mimicry in response. Both need to be present in order for arms race to occur.
339
Define Photosynthetic Autotrophs (Terrestrial)
Harness the sun’s energy to produce their own “food”
340
Define Chemosynthetic Autotrophs (Aquatic)
Bacteria use energy from chemical reactions (ocean rifts near hydrothermal vents discharge nutrients)
341
A major difference between primary and secondary production in ecosystems is that secondary production involves what?
Obtaining energy from organic, rather than inorganic compounds
