ECOLOGY TEST REVIEW

DR. BERTOLOTTI

A

Which of the following levels of organization is arranged in the correct sequence from most to least inclusive?• A) ecosystem, community, population, individual• B) community, ecosystem, individual, population• C) individual, population, community, ecosystem• D) population, ecosystem, individual, community• E) individual, community, population, ecosystem

6. C 7. B8. D9. E10. A

A. tropical rain forest B. taiga C. arctic tundra

D. temperate grassland E. desert

• 6. Permafrost; temperatures range from approximately -50°C to +25°C; a growing season of 60 days or less

• 7. Over 10 inches of precipitation per year; long, cold winters and short summers; dominant vegetation is gymnosperm

• 8. Lack of water common in summer; seasonal temperature variations; maintained by periodic fires

• 9. Less than 10 inches of precipitation per year; extremes of hot and cold throughout the year; large daily temperature variations

• 10. This biome has the greatest diversity of species.

E

Two barnacles, Balanus and Chthamalus, can both survive on the lower rocks just above the low tide line on the Scottish coast, but only Balanus actually does so, with Chthamalus adopting a higher zone. Which of the following best accounts for this niche separation?

• A) mutualism• B) predation of Chthamalus by Balanus• C) primary succession• D) cooperative displacement• E) competitive exclusion

E

Which of the following statements is (are) true?A) At any point in time, it is impossible for consumers to outnumber producers in an ecosystem.B) An ecosystem's trophic structure determines the rate at which energy cycles within the system.C) Chemoautotrophic prokaryotes near deep-sea vents are primary producers.D) There has been a well-documented increase in atmospheric carbon dioxide over the past several decades.E) Both C and D are true.

MUTUALISM

Some scientists believe that early in the history of the planet, different types of microbes joined together to form a new type of organism. At the time, certain bacteria had the ability to convert sunlight to chemical energy, or generate chemical energy from oxygen. These microbes were engulfed by larger bacteria, forming a microbial symbiosis. The host cell protected the smaller microbe inside, while benefitting from the skills of its new partner.

In the beginning, the two bacteria could still function separately. Eventually, the microbes living inside lost the ability to survive on their own, and they became specialized components of the host cells. These structures later became the mitochondria and chloroplasts of eukaryotic cells. Mitochondria generate energy using oxygen, and chloroplasts convert sunlight into chemical energy in plant cells. Supporting this theory is the fact that mitochondria and chloroplasts both have their own DNA, separate than that found in the nucleus of the cell.

What type of symbiosis is this an example of?

A

How do the activities of a keystone species affect the biodiversity of an ecosystem?

A. They increase biodiversity.

B. They decrease biodiversity

C. They have no effect on biodiversity.

D. Biodiversity remains the same but the species change

A

A rocky island appears as oceanic waters recede. Which of the following forms of vegetation would probably appear first on the bare rocks?

1. lichens 2. weeds 3. shrubs 4. pioneer trees

E

• Which point on the curve in the diagram above best represents the carrying capacity of the environment for the population shown?

• A. A• B. B• C. C• D. D• E. E

A

All of the following are density-dependent factors that limit animal populations EXCEPT• A. weather D. food

competition• B. predation E. mortality• C. birthrate

MUTUALISM

Some fungi increase the absorption of water and nutrients by the plants, and benefit from the compounds produced by the

plants during photosynthesis. The fungus also protects the roots from diseases. Some fungi form extensive networks beneath the ground, and have been known to transport

nutrients between plants and trees in different locations.

What type of symbiosis is this an example of?

AThe exotic species "kudzu" plant.

How might an introduced plant species kill native plant species

A. Its rapid growth can deprive native plants of sunlight. B. Its rapid growth can deprive native plants of food. C. It can cause soil loss from erosion. D. Its rapid growth can deprive native plants of oxygen.

D

What element is most closely correlated with Eutrophication?

a) Sulfur

b) Carbon

c) Phosphorus

d) Nitrogen

B

The graph below shows changes in a population of wild sheep that were introduced to the island of Tasmania in the early 1800s. 20. The type of population growth represented by that portion of the graph line enclosed in the bracket is most accurately termed • A. stable• B. exponential• C. density-dependent• D. arithmetic• E. decelerating

E

Which of the following organisms is most likely to be located at the apex of the pyramid of biomass?• A. grass• B. grasshopper• C. snake• D. mouse• E. hawk

E

All of the following statements concerning characteristics of predator-prey relationships are correct EXCEPT:• A. A rise in the population of prey is often followed by a rise in the

population of predators.• B. A rise in the population of predators is followed by a decrease in

the population of prey.• C. Camouflage is an adaptation that protects prey.• D. The production of large numbers of offspring within very short

periods of time ensures the survival of some prey populations.• E. The population of predators most often eliminates the population

of prey.

C

A lichen is a combination of fungus and algae that lives on the sides of trees, rocks, and other materials. The fungus provides the algae with water and minerals and the algae uses the water and minerals to make food for both organisms. What type of relationship does the lichen represent?

A. parasitism B. commensalism C. mutualism D. competition

C

Why do energy pyramids and biomass pyramids usually have a similar shape? A. An energy pyramid cannot contain more energy than organisms need B. As energy is lost, more biomass can be supported C. The amount of biomass on any level cannot be greater than the available energy can support D. Both energy and biomass are lost to the environment at equal rates

B

All of the following statements about the diagram are correct EXCEPT: A. The grasshopper is an herbivore.B. Only two trophic levels are depicted.C. The mouse and grasshopper are at the same trophic level.D. The grass is a producer.E. All of the organisms except grass are consumers, regardless of position.

C

• During the carbon cycle, which of the following carbon compounds would be utilized as an energy source by heterotrophs? • A. calcium carbonate• B. carbonic acid• C. organic molecules• D. carbon dioxide• E. carbon monoxide

A

Leeches have been used for medicinal purposes. The leech benefits by getting blood (food) from humans. How do humans benefit from the mutualistic relationship?

• A. the leech helps improve blood flow in the human • B. the leech reduces the humans chance

of a bacterial infection • C. the leech improves the cosmetic look

of the human

B

Why is population a density dependent limiting factor for disease?

A. The less crowded an area is, the easier it is for disease to spread. B. The more crowded an area is, the easier it is for disease to spread. C. Both of the above

A

D

4

Which statement best describes some organisms in the food web shown below?

1. Minnows and fish are primary consumers. 2. Algae and floating plants are decomposers. 3. Aquatic crustaceans are omnivores. 4. Raccoons, fish, and ducks are secondary consumers.

DWhy might an introduced animal species, such as the rabbit in Australia overrun native species in an ecosystem?

A. Its population size is smaller than those of native species B. It is more energy efficient, so it eats less food. C. It is a predator of the native species. D. It often has no natural enemies

DA dung beetle and the larger animals that provide the dung. (A dung beetle gathers the dung [manure] of other animals and rolls it into a ball to move it. The beetle feeds on the ball, making it a decomposer.)

A. PredationB. ParasitismC. MutualismD. Commensalism

C

Which of the following is a cause and effect relationship that seems to be supported by the graph?

A. Carbon dioxide levels have no effect on average global temperatures. B. As carbon dioxide levels increase, average global temperatures decrease. C. As carbon dioxide levels increase, average global temperatures increase. D. As average global temperatures increase, carbon dioxide levels decrease

D

Which of the following is true about secondary consumers in an ecosystem? • A. They eat only plants.• B. They are eaten by primary consumers.• C. They are smaller and weaker than are primary consumers.• D. They are fewer in number than are primary consumers.• E. They contain the greatest total biomass in the system.

MUTUALISM

Bacteria live inside the human digestive system. These microbes break down food and produce vitamins that humans need. In return, the bacteria benefit from the stable environment inside the intestines. Bacteria also colonize human skin. The bacteria obtain nutrients from the surface of the skin, while providing people with protection against more dangerous microbes.

What type of symbiosis is this an example of?

B

• In the nitrogen cycle, the transformation of gaseous nitrogen into nitrogen-containing compounds is performed primarily by• A. fungi• B. bacteria• C. green plants• D. herbivores• E. carnivores

A

• The organic and inorganic materials in all the organisms in the diagram will eventually return to the environment by the action of

• A. decomposers• B. producers• C. primary consumers• D. secondary consumers• E. top carnivores

E

Which of the following best explains why there are seldom more than five trophic levels in a food chain?

• A. Most carnivores function at more than one trophic level.• B. Trophic levels above this number contain too many

individuals.• C. Top carnivores are too few in number to prey effectively.• D. The ecosystem contains too much biomass.• E. Energy is lost from each trophic level.

E

An insect that has evolved to resemble a plant twig will probably be able to avoid• A) competition. • B) parasitism. • C) commensalism. • D) symbiosis. • E) predation.

B

Which of the following does not represent a potential threat to biodiversity?

A) importing a European insect into the United States to control an undesirable weedB) letting previously used farmland go fallow and begin to fill with weeds and shrubsC) building a new mall on a previously unoccupied piece of midwestern prairie.D) harvesting all of the oysters from an oyster bed off the Atlantic coastE) shooting wolves because they pose a threat to cattle farmers

C

A cow's herbivorous diet indicates that it is a(n)• A) secondary consumer.• B) decomposer.• C) primary consumer.• D) autotroph.• E) producer.

C

A population is correctly defined as having which of the following characteristics?• I. inhabiting the same general area• II. individuals belonging to the same species• III. possessing a constant and uniform density and dispersion

• A) I only • B) III only • C) I and II only • D) II and III only • E) I, II, and III

C

Dwarf mistletoes are flowering plants that grow on certain forest trees. They obtain nutrients and water from the vascular tissues of the trees. The trees derive no known benefits from the dwarf mistletoes. Which of the following best describes the interactions between dwarf mistletoes and trees?

• A) competition • B) mutualism • C) parasitism • D) commensalism • E) facilitation

B

Zebra mussel populations are growing explosively in the river systems of the central United States. The best explanation for this unchecked population growth is that

A) they muddy the water around them, making it difficult for their natural enemies to see them.

B) predators are too few to slow down population growth of the mussels.

C) a mutation caused by pollution has increased their reproductive rate.

D) they are better adapted to the environment than competing species.

E) they are feeding on a source of food that had previously been underutilized.

C

Eutrophication is a phenomenon where excessive amount of nutrients are added to a marine ecosystem. These nutrients cause plant life like algae to multiple rapidly, which swells their populations to very high densities. In freshwater ecosystems, the algae can become so dense that it can turn ponds, lakes or even smaller rivers green. The algae grows to an unreasonable level at a very fast rate. The algae are known as phytoplankton and are microscopic, single-celled organisms known as phytoplankton.

A body of water that is experiencing eutrophication and a resulting bloom can be quickly devastated. Eutrophication affects all living organisms in the area including fish, birds and mammals. The top layer of phytoplankton cause such a build-up on the surface that they accumulate sediment. When this occurs the sunlight is blocked and it will choke off the plant life below the surface. The phytoplankton will also cause less surface area for the water to interface with water. As a result, there will be less oxygen available in the water. As oxygen will continue to deplete, it can have a negative effect on life as there will be less oxygen to support the organisms below the surface that depend on the oxygen from plants and that diffuses into the water.

Scientist 1

The cause of the eutrophication is not known. The frequency and increasing incidents of eutrophication point to human farming activities as the cause. The growth of the phytoplankton is caused by runoff that contains multiple sources of nitrates that are also found in fertilizer. The nitrates allow for the phytoplankton to grow rapidly. The human farming activity is the root cause of the eutrophication of the area. The key to the solution is moving the drainage so the runoff from the human farming activity cannot reach the water source or moving the farms.

Scientist 2

Sometimes eutrophication can happen naturally without any real cause. Sometimes when there are periods of heavy rain the increase in rain water leads to an imbalance in the pH of the water. This in turn creates favorable conditions for the phytoplankton to grow and proliferate. This is a natural cycle that also ensures that too many fish and other animals do not build up in a freshwater source. This type of bloom is nature’s way of eliminating overpopulation with an abiotic factor. Although many organisms will die as a result, it will help to thin the numbers of organisms and ensure a healthier freshwater source.

According to Scientist 1, which of the following is the cause of the eutrophication?

A. A change in the pH of the water. B. The increasing changes in phytoplankton. C. Agricultural run-off from human activity. D. The build-up of phosphates in the body of water.

B

Eutrophication is a phenomenon where excessive amount of nutrients are added to a marine ecosystem. These nutrients cause plant life like algae to multiple rapidly, which swells their populations to very high densities. In freshwater ecosystems, the algae can become so dense that it can turn ponds, lakes or even smaller rivers green. The algae grows to an unreasonable level at a very fast rate. The algae are known as phytoplankton and are microscopic, single-celled organisms known as phytoplankton.

A body of water that is experiencing eutrophication and a resulting bloom can be quickly devastated. Eutrophication affects all living organisms in the area including fish, birds and mammals. The top layer of phytoplankton cause such a build-up on the surface that they accumulate sediment. When this occurs the sunlight is blocked and it will choke off the plant life below the surface. The phytoplankton will also cause less surface area for the water to interface with water. As a result, there will be less oxygen available in the water. As oxygen will continue to deplete, it can have a negative effect on life as there will be less oxygen to support the organisms below the surface that depend on the oxygen from plants and that diffuses into the water.

Scientist 1

The cause of the eutrophication is not known. The frequency and increasing incidents of eutrophication point to human farming activities as the cause. The growth of the phytoplankton is caused by runoff that contains multiple sources of nitrates that are also found in fertilizer. The nitrates allow for the phytoplankton to grow rapidly. The human farming activity is the root cause of the eutrophication of the area. The key to the solution is moving the drainage so the runoff from the human farming activity cannot reach the water source or moving the farms.

Scientist 2

Sometimes eutrophication can happen naturally without any real cause. Sometimes when there are periods of heavy rain the increase in rain water leads to an imbalance in the pH of the water. This in turn creates favorable conditions for the phytoplankton to grow and proliferate. This is a natural cycle that also ensures that too many fish and other animals do not build up in a freshwater source. This type of bloom is nature’s way of eliminating overpopulation with an abiotic factor. Although many organisms will die as a result, it will help to thin the numbers of organisms and ensure a healthier freshwater source.

What is the main point of disagreement between Scientist 1 and Scientist 2? A. The source of the nitrogen. B. The root cause of the eutrophication. C. The effects of the lack of oxygen. D. The effect of the plant life in the aquatic ecosystem.

C

Eutrophication is a phenomenon where excessive amount of nutrients are added to a marine ecosystem. These nutrients cause plant life like algae to multiple rapidly, which swells their populations to very high densities. In freshwater ecosystems, the algae can become so dense that it can turn ponds, lakes or even smaller rivers green. The algae grows to an unreasonable level at a very fast rate. The algae are known as phytoplankton and are microscopic, single-celled organisms known as phytoplankton.

A body of water that is experiencing eutrophication and a resulting bloom can be quickly devastated. Eutrophication affects all living organisms in the area including fish, birds and mammals. The top layer of phytoplankton cause such a build-up on the surface that they accumulate sediment. When this occurs the sunlight is blocked and it will choke off the plant life below the surface. The phytoplankton will also cause less surface area for the water to interface with water. As a result, there will be less oxygen available in the water. As oxygen will continue to deplete, it can have a negative effect on life as there will be less oxygen to support the organisms below the surface that depend on the oxygen from plants and that diffuses into the water.

Scientist 1

The cause of the eutrophication is not known. The frequency and increasing incidents of eutrophication point to human farming activities as the cause. The growth of the phytoplankton is caused by runoff that contains multiple sources of nitrates that are also found in fertilizer. The nitrates allow for the phytoplankton to grow rapidly. The human farming activity is the root cause of the eutrophication of the area. The key to the solution is moving the drainage so the runoff from the human farming activity cannot reach the water source or moving the farms.

Scientist 2

Sometimes eutrophication can happen naturally without any real cause. Sometimes when there are periods of heavy rain the increase in rain water leads to an imbalance in the pH of the water. This in turn creates favorable conditions for the phytoplankton to grow and proliferate. This is a natural cycle that also ensures that too many fish and other animals do not build up in a freshwater source. This type of bloom is nature’s way of eliminating overpopulation with an abiotic factor. Although many organisms will die as a result, it will help to thin the numbers of organisms and ensure a healthier freshwater source.

Both scientists would likely agree that eutrophication is A. algae that will occasionally grow in aquatic ecosystems due to human activities. B. a bloom of phytoplankton that grows in response to high levels of phosphates. C. a large build-up of algae that grows at a rapid rate in a body of water. D. an explosion of algae due to natural factors and the need to reduce overpopulation.

B