Ecology Community Species Interactions Questions and Answers

Question 1

In a classic experiment, G.F.
Gause cultured two species of Paramecium, P. aurelia and P. caudatum, in the same environment with a fixed amount of daily food.
When grown together, P. aurelia thrived, while the P. caudatum population declined and eventually went extinct.
This outcome is a direct example of which ecological principle?

Accepted Answer

Competitive exclusion

Answer

Resource partitioning

Answer

Character displacement

Answer

Trophic cascade

Question 2

Which of the following scenarios best illustrates the concept of resource partitioning?

Accepted Answer

Five species of coexisting warblers feeding on insects in different zones of the same spruce trees.

Answer

A lion pride successfully driving a clan of hyenas away from a recent kill.

Answer

The reintroduction of wolves to an ecosystem leading to an increase in aspen trees due to reduced elk populations.

Answer

A harmless hoverfly evolving to have the same black and yellow coloration as a stinging wasp.

Question 3

In a Pacific kelp forest ecosystem, sea otters prey on sea urchins. The sea urchins, in turn, graze on kelp. The presence of sea otters maintains a healthy kelp forest, which supports a wide variety of other species. Based on this role, the sea otter is best described as a(n):

Accepted Answer

Keystone species

Answer

Apex predator

Answer

Indicator species

Answer

Foundation species

Question 4

A non-venomous kingsnake has coloration and banding patterns very similar to the highly venomous coral snake. Predators that have learned to avoid the dangerous coral snake will also avoid the harmless kingsnake. This type of defensive adaptation is known as:

Accepted Answer

Batesian mimicry

Answer

Commensalism

Answer

Müllerian mimicry

Answer

Aposematism

Question 5

The removal of a top predator, such as the grey wolf, from an ecosystem results in a dramatic increase in the elk population. This leads to the overgrazing of willow and aspen trees, which in turn negatively affects beaver populations that rely on these trees for food and dam construction. This chain of indirect effects across multiple trophic levels is called a:

Accepted Answer

Trophic cascade

Answer

Competitive exclusion event

Answer

Symbiotic shift

Answer

Niche displacement

Question 6

Cattle egrets are birds that are often found foraging in fields among cattle. The cattle's movements stir up insects from the ground, which the egrets then eat. The cattle are unaffected by the presence of the egrets. What type of symbiotic relationship does this represent?

Accepted Answer

Commensalism

Answer

Mutualism

Answer

Parasitism

Answer

Competition