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AP Environmental Science Practice Quiz: Introduction to Ecosystems

Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026

Test your understanding with short quizzes. This quiz has 10 questions to check your progress.

Question 1 of 10

According to the provided text, which of the following is the most direct cause of competition between or within species?

All Questions (10)

According to the provided text, which of the following is the most direct cause of competition between or within species?

A) The presence of a predator

B) The establishment of a symbiotic relationship

C) The availability of unlimited resources

D) The existence of limited resources

Correct Answer: D

The text states, 'Competition can occur within or between species in an ecosystem where there are limited resources,' directly linking resource scarcity to the occurrence of competition.

In a relationship where a lion hunts and consumes a zebra, how is the lion best classified?

A) Prey

B) Predator

C) Parasite

D) Symbiont

Correct Answer: B

The text defines a predator as 'an organism that eats another organism.' In this scenario, the lion is the organism that eats the zebra.

Which term describes a close and long-term interaction between two different species in an ecosystem?

A) Competition

B) Predation

C) Symbiosis

D) Resource partitioning

Correct Answer: C

The content explicitly defines symbiosis as 'a close and long-term interaction between two species in an ecosystem.'

What is the primary function of resource partitioning in an ecosystem?

A) To increase the intensity of competition for survival

B) To ensure one species out-competes another for all resources

C) To reduce the negative impact of competition on survival

D) To establish a predator-prey relationship

Correct Answer: C

The provided text states, 'Resource partitioning can reduce the negative impact of competition on survival.'

Based on the provided information, which of the following are all categorized as types of symbiosis?

A) Predation, Competition, and Mutualism

B) Mutualism, Commensalism, and Parasitism

C) Competition, Parasitism, and Commensalism

D) Resource partitioning, Predation, and Symbiosis

Correct Answer: B

The text clearly lists the types of symbiosis: 'Types of symbiosis include mutualism, commensalism, and parasitism.'

If two species of birds in the same tree rely on the same limited type of insect for food, a sudden decrease in the insect population would most likely intensify which interaction between the bird species?

A) Mutualism

B) Competition

C) Parasitism

D) Commensalism

Correct Answer: B

The decrease in the insect population makes a key resource more limited. The text explains that competition occurs 'where there are limited resources,' so the struggle for the remaining insects would intensify.

In a predator-prey relationship, the organism that is eaten by another is known as the:

A) Predator

B) Competitor

C) Host

D) Prey

Correct Answer: D

The text defines the predator as the organism that eats another. By definition, the organism that is eaten is the prey.

The availability of which of the following most directly influences the intensity of competition and other species interactions?

A) Predators

B) Resources

C) Symbiotic partners

D) Prey

Correct Answer: B

The first point in the content states, 'Explain how the availability of resources influences species interactions.' This is reinforced by the point on competition, which occurs 'where there are limited resources.'

Two species of grasses in a field compete for the same limited soil nutrients. If one species develops deeper roots to access nutrients the other cannot reach, this is a behavioral change that exemplifies a strategy to achieve:

A) A predator-prey reversal

B) A parasitic relationship

C) Resource partitioning

D) Increased direct competition

Correct Answer: C

By developing deeper roots, one species is utilizing a portion of the resource (nutrients deeper in the soil) that the other cannot, thereby dividing the resource. This is an example of resource partitioning, which reduces the negative impact of their competition.

Which of the following interactions is NOT listed as a type of symbiosis in the provided text?

A) Mutualism

B) Competition

C) Commensalism

D) Parasitism

Correct Answer: B

The text identifies mutualism, commensalism, and parasitism as types of symbiosis. Competition is described as a separate type of interaction that occurs over limited resources.