Biology Test Biology Ecology and Evolution 4

Question 1

What is 'biological magnification' (biomagnification) in an ecosystem?

Accepted Answer

The accumulation of toxins at higher trophic levels

Answer

The increase in population size over time

Answer

The enlargement of organisms through evolution

Answer

The amplification of genetic mutations

Question 2

Which concept explains why two species with identical ecological niches cannot coexist in the same habitat?

Accepted Answer

Competitive exclusion principle

Answer

Island biogeography theory

Answer

Lotka-Volterra model

Answer

Intermediate disturbance hypothesis

Question 3

What type of natural selection favors individuals at both extremes of a trait distribution over those in the middle?

Accepted Answer

Disruptive selection

Answer

Stabilizing selection

Answer

Directional selection

Answer

Sexual selection

Question 4

How does mutualism differ from commensalism in terms of ecological benefit?

Accepted Answer

Mutualism benefits both species; commensalism benefits only one

Answer

Mutualism harms one species; commensalism harms both

Answer

Both mutualism and commensalism benefit only one species

Answer

Mutualism is always obligate; commensalism is always facultative

Question 5

In population ecology, what does the logistic growth model add to the exponential growth model?

Accepted Answer

Carrying capacity (K)

Answer

Age structure

Answer

Immigration and emigration rates

Answer

Predation pressure

Question 6

Which evolutionary mechanism involves individuals from one population moving to and breeding with another population?

Accepted Answer

Gene flow

Answer

Genetic drift

Answer

Natural selection

Answer

Sexual selection

Question 7

What defines a 'climax community' in ecological succession?

Accepted Answer

A stable, self-sustaining community representing the endpoint of succession

Answer

The first community to colonize bare rock

Answer

A transient community disrupted by fire or flooding

Answer

A community dominated by a single species