Natural Selection Practice Questions
AP (Advanced Placement) · AP Biology · 151 free MCQs with instant results and detailed explanations.
151
Total
46
Easy
77
Medium
28
Hard
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Sample Questions from Natural Selection
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
Which of the following best describes natural selection?
A.
A process where individuals with advantageous traits survive and reproduce.
B.
A method for plants to adapt to their environment.
C.
An event that eliminates all members of a species.
D.
A random process affecting all individuals equally.
Show Answer & Explanation
Correct Answer: A
Natural selection is the process where organisms better adapted to their environment tend to survive and produce more offspring. This is because advantageous traits enhance survival and reproduction.
Q2
Easy
If a population of beetles has a range of colors but the environment favors darker beetles, which outcome is most likely after several generations?
A.
The population will have an equal distribution of colors.
B.
The population will consist mostly of darker beetles.
C.
The population will become extinct due to lack of color variation.
D.
The population will develop a new color to adapt.
Show Answer & Explanation
Correct Answer: B
Over several generations, natural selection will favor darker beetles, leading to increased survival and reproduction rates among them. This will result in a population dominated by darker beetles.
Q3
Easy
In a certain species of fish, larger individuals have a higher chance of finding mates. If the average size of this fish species increases over time, what concept does this illustrate?
A.
Genetic drift.
B.
Artificial selection.
C.
Sexual selection.
D.
Stabilizing selection.
Show Answer & Explanation
Correct Answer: C
This scenario illustrates sexual selection, where individuals with traits that are favorable for attracting mates (larger size) are more likely to reproduce, leading to a gradual increase in that trait within the population.
Q4
Medium
Which of the following best describes the role of genetic variation in natural selection?
A.
It allows populations to adapt to changing environments.
B.
It decreases the survival rates of organisms.
C.
It eliminates all harmful mutations.
D.
It ensures that all offspring are identical.
Show Answer & Explanation
Correct Answer: A
Genetic variation is crucial for natural selection because it provides the raw material for adaptation. Without variation, populations cannot respond to environmental changes.
Q5
Medium
In a population of beetles, green beetles are more conspicuous to predators than brown beetles. If brown beetles survive and reproduce more effectively, which type of selection is occurring?
A.
Disruptive selection
B.
Stabilizing selection
C.
Directional selection
D.
Sexual selection
Show Answer & Explanation
Correct Answer: C
This scenario describes directional selection, where one phenotype (brown beetles) is favored over others (green beetles), leading to increased frequency of the favored trait in the population.
Q6
Medium
If a population of rabbit exhibits a phenotypic ratio of 3:1 for fur color, what can be inferred about their genetic makeup assuming simple Mendelian inheritance?
A.
The population is homozygous for fur color.
B.
The population is heterozygous for fur color.
C.
The trait is sex-linked.
D.
The trait is polygenic.
Show Answer & Explanation
Correct Answer: B
A 3:1 phenotypic ratio typically indicates a heterozygous condition in a monohybrid cross where one allele is dominant and one is recessive.
Q7
Medium
A scientist observes that a certain species of fish has developed a trait for larger fins. This trait appears to give them better swimming efficiency. If this trait becomes more common over generations, which concept does this best illustrate?
A.
Artificial selection
B.
Co-evolution
C.
Adaptive evolution
D.
Genetic drift
Show Answer & Explanation
Correct Answer: C
The increase in a trait that enhances survival and reproductive success, like larger fins for better swimming, exemplifies adaptive evolution as the population becomes better suited to its environment.
Q8
Hard
In a certain population of beetles, individuals exhibit a range of coloration from green to brown. If the brown beetles are more visible to predators in a green environment, which of the following statements best explains the potential outcome of this scenario over several generations?
A.
The population will shift towards more brown individuals due to mutation.
B.
The population will decrease in the number of brown individuals due to increased predation.
C.
The population will remain stable as coloration does not affect survival.
D.
The green coloration will become a recessive trait in the population.
Show Answer & Explanation
Correct Answer: B
The increased visibility of brown beetles to predators implies higher predation rates on these individuals, leading to a reduction in their population over generations. Natural selection favors the green beetles, which are better camouflaged.
Q9
Hard
In a study of a population of fish in a lake, it was found that larger individuals had a higher reproductive success than smaller individuals. If the average size of the fish increases over time, what pattern of natural selection does this represent?
A.
Stabilizing selection
B.
Directional selection
C.
Disruptive selection
D.
Sexual selection
Show Answer & Explanation
Correct Answer: B
The increase in average size of the fish population indicates that larger individuals are favored, which is characteristic of directional selection. This type of selection pushes the population's traits toward one extreme.
Q10
Hard
A population of beetles exhibits a range of colors from green to brown. If a sudden environmental change causes the green beetles to be more visible to predators, which of the following scenarios best illustrates the process of natural selection?
A.
The number of brown beetles increases over time as they are less likely to be eaten.
B.
The green beetles start to develop a thicker carapace.
C.
The beetles migrate to a different habitat.
D.
All beetles in the population reproduce equally.
Show Answer & Explanation
Correct Answer: A
Natural selection favors traits that improve survival. In this case, brown beetles are less visible to predators, leading to their increased survival and reproduction, which demonstrates natural selection.
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Natural Selection — AP (Advanced Placement) AP Biology Practice Questions Online
This page contains 151 practice MCQs for the chapter Natural Selection in AP (Advanced Placement) AP Biology. The questions are organized by difficulty — 46 easy, 77 medium, 28 hard — so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit.