FREE Ecology Community Species Interactions Questions and Answers

Question 1

In a rocky intertidal zone, the presence of the sea star *Pisaster ochraceus* prevents the mussel *Mytilus californianus* from dominating the habitat and excluding other species like barnacles and algae.
Which ecological concept does the sea star BEST exemplify?

Accepted Answer

Keystone species

Answer

Foundation species

Answer

Indicator species

Answer

Pioneer species

Question 2

The reintroduction of gray wolves into Yellowstone National Park led to a decrease in the elk population. This, in turn, allowed for the recovery of willow and aspen trees, which then supported an increase in the beaver population. This chain of effects is a clear example of:

Accepted Answer

A trophic cascade

Answer

Competitive exclusion

Answer

Resource partitioning

Answer

Character displacement

Question 3

Which of the following scenarios describes a commensal relationship?

Accepted Answer

A cattle egret feeding on insects stirred up by a grazing cow, where the cow is unaffected.

Answer

A tick feeding on the blood of a deer, harming the deer in the process.

Answer

Bees gathering nectar from a flower, which helps the flower with pollination.

Answer

Two species of barnacles competing for limited space on a rock.

Question 4

Two species of finches live on the same island. Where their territories overlap, their beak sizes show greater differences than where they live separately. This allows them to specialize on different seed sizes, reducing direct competition. This evolutionary divergence is known as:

Accepted Answer

Character displacement

Answer

Competitive release

Answer

Resource partitioning

Answer

Niche generalization

Question 5

The harmless hoverfly has black and yellow banding that closely resembles that of a stinging wasp. Predators that have learned to avoid wasps will also avoid the hoverfly. This is an example of which type of mimicry?

Accepted Answer

Batesian mimicry

Answer

Aggressive mimicry

Answer

Müllerian mimicry

Answer

Automimicry

Question 6

When two species utilize the same limited resource in different ways, at different times, or in different locations to minimize competition, they are engaging in:

Accepted Answer

Resource partitioning

Answer

Competitive exclusion

Answer

Amensalism

Answer

Mutualism