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AP Biology Practice Quiz: Variations in Populations

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

Test your understanding with short quizzes. This quiz has 7 questions to check your progress.

Question 1 of 7

According to the provided text, what is the primary effect of high genetic diversity on a population when it faces a new environmental pressure?

All Questions (7)

According to the provided text, what is the primary effect of high genetic diversity on a population when it faces a new environmental pressure?

A) It guarantees the survival of all individuals.

B) It increases the population's resilience and ability to withstand the pressure.

C) It causes the population to decline rapidly.

D) It has no significant effect on the population's survival.

Correct Answer: B

The text explicitly states that 'Genetically diverse populations are more resilient to environmental changes' and that genetic diversity affects a population's 'ability to withstand environmental pressures.'

A specific population of plants has very low genetic variation. A novel, highly infectious fungus is introduced into its environment. Based on the provided information, which of the following outcomes is most likely?

A) The population will easily adapt because all individuals are genetically similar.

B) The population is at a high risk of extinction because few, if any, individuals may have traits to resist the fungus.

C) The genetic variation of the population will rapidly increase in response to the new threat.

D) The fungus will have no effect, as genetic variation only relates to climate pressures.

Correct Answer: B

The text states that genetically diverse populations are 'less at risk of extinction.' Therefore, a population with low genetic variation would be more at risk when facing a significant environmental pressure like a new disease.

Which statement best describes the relationship between genetic variation and population dynamics as presented in the text?

A) Populations with low genetic variation have the most stable dynamics.

B) The level of genetic variation is a key factor influencing a population's ability to persist through environmental changes.

C) Population dynamics are determined entirely by environmental factors, not genetic variation.

D) High genetic variation leads to unpredictable and chaotic population dynamics.

Correct Answer: B

The text links the level of genetic variation directly to population dynamics, explaining that this variation influences resilience and the ability to withstand pressures, which are key components of how a population changes over time.

A conservation program is attempting to reintroduce a species into a habitat that is known for its fluctuating environmental conditions. To maximize the chances of long-term survival, the biologists should prioritize selecting individuals that...

A) come from a single, highly-adapted lineage to ensure uniformity.

B) are the largest and strongest, regardless of their genetic background.

C) represent a high degree of genetic diversity from the source population.

D) have been raised in a controlled, stable laboratory environment.

Correct Answer: C

The provided text emphasizes that genetic diversity allows a population to withstand environmental pressures and changes. Therefore, to succeed in a fluctuating environment, a reintroduced population with high genetic diversity would be the most resilient.

A population with a lower risk of extinction is most likely to have which of the following characteristics?

A) A low level of genetic variation.

B) A high level of genetic diversity.

C) A small population size.

D) A highly specialized diet.

Correct Answer: B

This is a direct interpretation of the text, which states, 'Genetically diverse populations are... less at risk of extinction.'

Two populations of the same species exist in different habitats. Population 1 lives in a stable, unchanging environment. Population 2 lives in an environment with frequent, unpredictable changes. According to the principles provided, why is genetic diversity likely more critical for the long-term survival of Population 2?

A) Genetic diversity is not important for Population 2, as the environment is too chaotic for adaptation.

B) The stable environment of Population 1 makes genetic diversity a disadvantage.

C) The frequent changes in Population 2's environment create selective pressures that a genetically diverse population is better equipped to withstand.

D) Genetic diversity only influences a population's ability to withstand disease, not environmental changes.

Correct Answer: C

This question requires applying the core concept. The text states genetic diversity helps populations withstand 'environmental pressures' and 'environmental changes.' Population 2 faces these conditions frequently, making the resilience conferred by genetic diversity essential for its persistence.

The ability of a species to withstand environmental pressures is directly affected by its...

A) geographic location.

B) social structure.

C) genetic diversity.

D) average age.

Correct Answer: C

The first sentence of the provided content directly states, 'Explain how the genetic diversity of a species or population affects its ability to withstand environmental pressures.' This question is a straightforward comprehension check of that statement.