Question 1

Which of the following best describes the difference between a population and a community in ecological terms?

Accepted Answer

A population includes all the members of a single species in a given location, while a community includes all the interacting populations in a given area.

Question 2

Which of the following is an example of a biotic factor in an ecosystem?

Accepted Answer

Predation by wolves

Question 3

Which equation best represents the process of photosynthesis carried out by autotrophs?

Accepted Answer

$$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6$ + 6O_2$$

Question 4

Which of the following organisms would be classified as a saprophyte?

Accepted Answer

A mushroom decomposing a fallen log

Question 5

In a food web, what is the primary role of decomposers?

Accepted Answer

To break down organic wastes and dead organisms into simpler substances for reuse

Question 6

Which of the following best explains why energy pyramids are always wider at the base than at the top?

Accepted Answer

Energy is lost as heat at each trophic level, so less is available to higher levels

Question 7

If only 10% of energy is transferred from one trophic level to the next, how much energy would be available to secondary consumers if producers have 10,000 kcal?

Accepted Answer

$$100$$ kcal

Question 8

Which of the following is an example of mutualism?

Accepted Answer

Lichens formed by algae and fungi living together

Question 9

Which process in the nitrogen cycle is responsible for converting atmospheric $$N_2$$ into a form usable by plants?

Accepted Answer

Nitrogen fixation

Question 10

A population of fish in a lake is limited by the amount of dissolved oxygen. What ecological concept does this illustrate?

Accepted Answer

Limiting factor

Question 11

Which of the following scenarios best illustrates ecological succession?

Accepted Answer

A forest regrows after a wildfire, starting with grasses and ending with mature trees

Question 12

Which of the following is a negative impact of human activity on ecosystems?

Accepted Answer

Importing organisms with no natural enemies

Question 13

Which of the following best defines a niche?

Accepted Answer

The role an organism plays in a community, including its use of resources and relationships

Question 14

Which of the following is a real-world example of biological control?

Accepted Answer

Using natural parasites to reduce pest populations

Question 15

Which of the following is a consequence of the loss of biodiversity in an ecosystem?

Accepted Answer

Decreased stability and resilience to environmental changes

Question 16

Which of the following pollutants is a major contributor to the greenhouse effect?

Accepted Answer

Carbon dioxide

Question 17

In a grassland food web, which organism would be considered a primary consumer?

Accepted Answer

Rabbit

Question 18

Which of the following best describes the process of transpiration in the water cycle?

Accepted Answer

Water vapor is released from plant leaves into the atmosphere

Question 19

If two species occupy the same niche in an ecosystem, what is the most likely outcome?

Accepted Answer

One species will outcompete and eliminate the other

Question 20

Which of the following actions is an example of conservation of resources?

Accepted Answer

Erosion control through reforestation

Ecology: Principles, Organization, and Human Impact

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