Question 1

Which of the following best defines mutualism in ecological terms?

Accepted Answer

Interactions between individuals of different species that benefit both partners ($$+/+).$$

Question 2

Which of the following is an example of an obligate mutualism?

Accepted Answer

Plants and mycorrhizal fungi

Question 3

A plant species can survive without its mutualistic partner, but benefits from the relationship. This is an example of:

Accepted Answer

Facultative mutualism

Question 4

Which of the following mutualisms is primarily trophic in nature?

Accepted Answer

Plants and mycorrhizal fungi

Question 5

What is the main benefit that mycorrhizal fungi receive from their plant partners?

Accepted Answer

Carbon compounds

Question 6

Which of the following statements about arbuscular mycorrhizal fungi (AMF) is correct?

Accepted Answer

AMF produce arbuscules, which are sites of exchange between plants and fungi.

Question 7

According to Hardie, how do mycorrhizal fungi improve plant water relations?

Accepted Answer

By providing more extensive contact with moisture in the rooting zone and extra area for water absorption

Question 8

In the mutualism between ants and bullhorn acacia, what is a direct benefit received by the ants?

Accepted Answer

Living space and food resources such as Beltian bodies and nectar

Question 9

Which of the following best describes the relationship between corals and zooxanthellae?

Accepted Answer

Zooxanthellae live within coral tissues, providing organic compounds via photosynthesis, while corals provide nutrients and a protected environment.

Question 10

What is the main benefit that zooxanthellae receive from their coral hosts?

Accepted Answer

Access to higher nutrient levels, especially nitrogen and phosphorus

Question 11

Glynn's research on coral protection mutualism found that:

Accepted Answer

Crustacean mutualists substantially improved the chances that corals would avoid attack by sea stars.

Question 12

Which of the following best explains why mutualisms are more common in stressful environments?

Accepted Answer

Organisms in stressful environments benefit more from cooperation, as mutualism can help them survive under challenging conditions.

Question 13

According to the theory of the evolution of mutualism, under what condition will mutualism evolve?

Accepted Answer

When the benefits of mutualism exceed the costs

Question 14

Which of the following is an example of a defensive mutualism?

Accepted Answer

Cleaner fish removing parasites from host fish

Question 15

A plant species produces flowers with a long corolla tube, and its main pollinator has a long tongue. This is an example of:

Accepted Answer

Reciprocal evolutionary change (coevolution)

Question 16

Which of the following best describes a successful mutualist?

Accepted Answer

Gives and receives benefits

Question 17

In a scenario where a coral species is protected by a crab mutualist, what would likely happen if the crab population declined significantly?

Accepted Answer

The coral would become more susceptible to sea star predation.

Question 18

Which of the following is NOT a benefit that plants receive from mycorrhizal fungi?

Accepted Answer

Increased carbon fixation

Question 19

Why might mutualisms become less important when resources are plentiful?

Accepted Answer

The benefits of cooperation are reduced when resources are not limiting.

Question 20

Which equation best represents the condition for the evolution of mutualism?

Accepted Answer

$$B \u003e C$$

Mutualism: Types, Examples, and Evolution in Biology

Study Guide - Practice Questions