Question 1

Which of the following best describes the concept of competitive exclusion in community ecology?

Accepted Answer

One species outcompetes another for a resource, leading to the local elimination of the weaker competitor.

Question 2

Resource partitioning allows ecologically similar species to coexist. Which scenario best illustrates resource partitioning?

Accepted Answer

Two lizard species occupy different parts of the same tree, one on sunny posts and the other on shady branches.

Question 3

Character displacement is most likely to occur in which situation?

Accepted Answer

Two species with overlapping distributions evolve differences in traits, such as beak depth, due to competition.

Question 4

Which equation is used to calculate Shannon’s Diversity Index for a community?

Accepted Answer

$$H = -\sum p_i \ln(p_i)$$

Question 5

A community has four species with equal relative abundance. What is the Shannon Diversity Index ($$H) $$for this community?

Accepted Answer

$$H = -4(0.25 \ln 0.25)$$

Question 6

Which of the following is an example of Batesian mimicry?

Accepted Answer

A harmless snake mimics the coloration of a venomous snake.

Question 7

Which interaction is described as a +/- relationship where one organism benefits and the other is harmed?

Accepted Answer

Parasitism

Question 8

Which adaptation is NOT a typical prey defense against predation?

Accepted Answer

Aggressive mimicry

Question 9

Which scenario best illustrates commensalism?

Accepted Answer

Barnacles living on whales, benefiting from movement but not affecting the whale.

Question 10

Facilitation differs from symbiosis in that:

Accepted Answer

Facilitation involves positive effects without direct contact.

Question 11

Which of the following is a real-world example of resource partitioning?

Accepted Answer

Anolis lizards occupying different parts of the forest, such as fence posts and shady branches.

Question 12

Which statement about trophic structure is correct?

Accepted Answer

A food web includes multiple species at each trophic level and complex feeding relationships.

Question 13

Which of the following is an example of mutualism?

Accepted Answer

Rhizobium bacteria forming nodules on bean roots, providing nitrogen while receiving carbohydrates.

Question 14

Which scenario best illustrates character displacement?

Accepted Answer

Two finch species on the same island evolve different beak depths due to competition.

Question 15

Which of the following is NOT a plant defense against herbivory?

Accepted Answer

Specialized teeth for detoxification

Question 16

Which equation would you use to calculate the relative abundance of a species in a community?

Accepted Answer

$$p_a = \frac{n_a}{N}$$

Question 17

Why are diverse communities more resistant to invasive species?

Accepted Answer

They have more species, so resources are more fully utilized, leaving fewer opportunities for invaders.

Question 18

Which of the following is an example of facilitation?

Accepted Answer

Black rush (Juncus gerardi) improves soil conditions, allowing more plant species to survive in salt marshes.

Question 19

Which statement about endoparasites and ectoparasites is correct?

Accepted Answer

Endoparasites live inside the host’s body, while ectoparasites live outside.

Community Ecology: Interspecific Interactions, Diversity, and Trophic Structure

Study Guide - Practice Questions