AP Biology Practice Quiz: Environmental Effects on Phenotype
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
All Questions (7)
A) Genotypic variation
B) Phenotypic plasticity
C) Genetic drift
D) Allelic frequency
Correct Answer: B
The provided text defines phenotypic plasticity as the phenomenon where one genotype can produce different phenotypes, which is a direct result of environmental factors influencing gene expression.
A) By causing permanent mutations in the DNA sequence.
B) By altering the number of chromosomes in the organism.
C) By influencing the process of gene expression.
D) By randomly changing the organism's genetic makeup.
Correct Answer: C
The text explicitly states that 'Environmental factors can influence gene expression, leading to phenotypic plasticity.' This identifies the influence on gene expression as the key mechanism for producing different phenotypes from a single genotype.
A) The genotype of the plant changing in response to the environment.
B) A spontaneous mutation occurring in the high-altitude plant.
C) The same genotype resulting in multiple phenotypes due to environmental differences.
D) The phenotype being determined solely by the plant's genetic code.
Correct Answer: C
The provided text explains that the same genotype can result in multiple phenotypes under different environmental conditions. Since the plants are genetically identical clones, their different growth patterns (phenotypes) must be due to the different altitudes (environmental conditions).
A) An organism's phenotype is a fixed trait determined exclusively at fertilization.
B) The environment plays a crucial role in how a genotype is expressed as a phenotype.
C) Genotype and phenotype are independent of each other.
D) All phenotypic variation within a population is due to genetic differences.
Correct Answer: B
The content emphasizes that environmental factors influence gene expression, which in turn affects the phenotype. This supports the conclusion that the environment is a key factor in the expression of a genotype.
A) The assumption that traits are inherited from parents.
B) The assumption that an organism's DNA can be transcribed into RNA.
C) The assumption that a specific genotype will always produce the exact same phenotype.
D) The assumption that natural selection acts on phenotypic variation.
Correct Answer: C
Phenotypic plasticity is the principle that a single genotype can lead to multiple phenotypes. This directly contradicts the idea of strict genetic determinism, which would assume that a given set of genes always results in one specific, predetermined physical trait.
A) The organism's genotype will change to better suit the new environment.
B) The organism's phenotype may change as a result of altered gene expression.
C) The organism will be unable to survive because its phenotype is fixed.
D) The organism's fundamental genetic code will be rewritten.
Correct Answer: B
The text states that different environmental conditions can cause the same genotype to result in multiple phenotypes by influencing gene expression. Therefore, a change in environment (from cold to warm) could lead to a change in the organism's phenotype.
A) One of the organisms must have acquired a new genotype after birth.
B) The organisms were exposed to different environmental factors that influenced their gene expression.
C) The initial assessment of their genotypes must have been incorrect.
D) Phenotypic expression is a purely random process unrelated to genes or environment.
Correct Answer: B
The core concept presented is that the same genotype can produce different phenotypes when exposed to different environmental conditions. This is due to the environment's influence on gene expression. Therefore, this is the most plausible explanation for the observed differences.