Question 1

Energy flow in an ecosystem is NOT cyclic because energy is

Accepted Answer

Energy flow in an ecosystem is not cyclic because energy is converted to heat during metabolic processes, and this heat is lost to the environment, making it unavailable for reuse by organisms.

Question 2

Is it possible that the carbon atoms in your body may have once made up the living tissues of another person or animal in earlier times? This is

Accepted Answer

Carbon cycles through the biosphere, moving between living organisms, the atmosphere, oceans, and the earth, allowing carbon atoms to be reused in different living tissues over time.

Question 3

Which of the following statements about the value of the nitrogen cycle to an ecosystem is NOT true?

Accepted Answer

Denitrification actually removes nitrogen from the ecosystem and releases it back into the atmosphere as nitrogen gas, not converting it to a form that plants can use.

Question 4

Which type of succession would occur after a volcanic eruption?

Accepted Answer

Primary succession occurs after a volcanic eruption because it starts on newly formed land where no soil exists, such as lava flows.

Question 5

Which of the following associations is incorrect?

Accepted Answer

Herbivores eat producers but do not perform photosynthesis.

Question 6

Which of the following statements about ecological pyramids is true?

Accepted Answer

Ecological pyramids based on biomass eliminate size as a factor because they measure the total mass of organisms at each trophic level, rather than the number of organisms or the energy content.

Question 7

Which of the following pairings of organisms and their method of obtaining nutrients is incorrect?

Accepted Answer

Detritivores obtain nutrients by consuming decomposing organic matter, not inorganic matter.

Question 8

Which of the following associations between organism and nutrient source is incorrect?

Accepted Answer

Humans are omnivores, not strictly carnivores, as they consume both plant and animal-based foods.

Question 9

All food chains begin with a photosynthetic producer.

Accepted Answer

The answer of All food chains begin with a photosynthetic...

Question 10

Energy flow in an ecosystem begins with

Accepted Answer

Energy flow in an ecosystem begins with autotrophs, which are organisms like plants and algae that produce their own food through photosynthesis, capturing energy from the sun.

Question 11

Excluding humans,which group of organisms is most likely to change the abiotic factors within an ecosystem?

Accepted Answer

All organisms can change the abiotic factors within an ecosystem. For example, producers release oxygen into the atmosphere, herbivores consume plants and change the plant community, detritivores decompose organic matter and release nutrients into the soil, and humans can alter the environment in a variety of ways.

Question 12

An ecosystem contains

Accepted Answer

An ecosystem includes both biotic (living organisms) and abiotic (non-living elements like water, soil, and climate) components, interacting as a system.

Question 13

In a grazing food chain,

Accepted Answer

In a grazing food chain, primary consumers feed on photosynthetic organisms, such as plants or algae, which are the primary producers.

Question 14

The only heterotrophs required in an ecosystem are

Accepted Answer

Decomposers are the only heterotrophs required in an ecosystem because they break down dead organisms and organic matter, releasing nutrients back into the soil for autotrophs to use. While herbivores, omnivores, and carnivores play important roles in the food chain, they are not essential for the ecosystem to function. Autotrophs, on the other hand, are not heterotrophs and are required in every ecosystem as the primary producers of energy.

Question 15

Consider the following food chain: hawk - rabbit - clover.Each species will contain a different amount of calories in its body (clover: 10 calories,rabbit: 500,and hawk: 1200).Each species has a different daily caloric requirement (clover: sunlight,rabbit: 100 calories,hawk: 300).How many rabbits,per day,does it take to support the hawk?

Accepted Answer

The hawk needs 300 calories per day. Each rabbit has 500 calories. So, it takes 300/500 = 0.6 rabbits per day to support the hawk.

Question 16

What is the correct sequence of organisms if a community is going through secondary succession?
 a.grasses establish themselves in the community
B.shrubs establish themselves in the community
C.soil formation occurs
D.trees establish themselves in the community

Accepted Answer

In secondary succession, soil is already present, so the sequence starts with grasses (a), followed by shrubs (b), and finally trees (d).

Question 17

Compared with the numbers of grasshoppers or deer,there are not as many mountain lions.The reason that large top-level carnivores are more rare in an ecosystem is because

Accepted Answer

Energy transfer in food chains is inefficient, with only about 10-20% of energy being passed to the next trophic level, limiting the number of top-level carnivores.

Question 18

Chemical cycling may involve all but which of the following?

Accepted Answer

The answer of Chemical cycling may involve all but which...

Question 19

Approximately what percentage of the energy in one trophic level is incorporated into the next trophic level?

Accepted Answer

The answer of Approximately what percentage of the energy in...

Question 20

Which of the following statement(s)about the hydrologic cycle is (are)true?

Accepted Answer

Some water does indeed evaporate from land and plants, a process known as evapotranspiration. Other statements are incorrect as they oversimplify or misrepresent the hydrologic cycle.

Quiz 45: Community and Ecosystem Ecology