AP Biology : Identify evolutionary change mechanisms

Study concepts, example questions & explanations for AP Biology

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Example Questions

Example Question #11 : Identify Evolutionary Change Mechanisms

Which of the following is not a type of mutation?

Possible Answers:

Genetic drift

Translocation

Inversion

Insertion

Correct answer:

Genetic drift

Explanation:

Mutations are changes in a cell’s genomic DNA sequence. Types of mutation include insertion, deletion, translocation, inversion, and duplication. An insertion is the addition of a nucleotide somewhere in the DNA; a deletion is the opposite. A translocation mutation involves the physical movement of DNA segments, and can occur within a chromosome or between different chromosomes. Genetic drift, on the other hand, is a type of sampling error that leads to the perceived allele frequency changing among generations.

Example Question #12 : Identify Evolutionary Change Mechanisms

Horizontal gene transfer is an example of what mechanism of evolution?

Possible Answers:

Mutation

Gene flow

Genetic drift

Natural selection

Correct answer:

Gene flow

Explanation:

Horizontal gene transfer is a method of transferring genetic material from one organism to another and is common among bacteria. Horizontal gene transfer is an example of gene flow, a mechanism of evolution that involves the flow of genes among populations, species, and organisms. Natural selection involves uneven survival and evolutionary fitness due to the advantages granted to certain individuals through genetic variation. A mutation is an unplanned change in the DNA sequence of a cell or organism. Genetic drift is the change in an allele frequency in a population due to random sampling.

Example Question #271 : Evolution And Genetics

Which of the following is true regarding the process of stabilizing selection?

Possible Answers:

It decreases genetic diversity

It favors individuals with extreme phenotypes

It increases genetic diversity

It has the same impact as disruptive selection

Correct answer:

It decreases genetic diversity

Explanation:

Stabilizing selection is a type of selection that decreases genetic diversity and stabilizes an optimum trait. In this situation, there is selection against extreme phenotypes. It is the opposite of disruptive selection and similar to purifying selection.

Example Question #272 : Evolution And Genetics

Which of the following is true regarding the process of directional selection?

Possible Answers:

Phenotype is pushed to both extremes

One phenotypic extreme is selectively advantageous

Allele frequency doesn't shift over time

It is the same as disruptive selection

Correct answer:

One phenotypic extreme is selectively advantageous

Explanation:

Directional selection is a type of natural selection in which one extreme phenotype is selectively advantageous. In other words, individuals with this trait are more likely to be reproductively successful. In this type of selection, one advantageous allele increases in frequency over time.

Example Question #273 : Evolution And Genetics

Which of the following is not true regarding the process of disruptive selection?

Possible Answers:

It is the opposite of stabilizing selection

It favors intermediates in the population

It favors extreme traits in the population

It increases genetic diversity

Correct answer:

It favors intermediates in the population

Explanation:

Disruptive selection is a type of natural selection in which the extremes of a phenotype are favored. This means that there is active selection against intermediates. It increases genetic diversity and is the opposite of stabilizing selection.

Example Question #271 : Evolution And Genetics

Which of the following best describes what happens to the frequency of a certain allele in the process of positive selection?

Possible Answers:

There is no change in the allele's frequency

The allele disappears from the gene pool

It increases in frequency

It decreases in frequency

Correct answer:

It increases in frequency

Explanation:

Positive selection is a type of natural selection in which the frequency of an allele increases.

Example Question #271 : Evolution And Genetics

Which of the following best describes what happens to the frequency of a certain allele in the process of negative selection?

Possible Answers:

The allele disappears from the gene pool

There is no change in the allele's frequency

It decreases in frequency

It increases in frequency

Correct answer:

It decreases in frequency

Explanation:

Negative selection is a type of natural selection in which the frequency of an allele decreases.

Example Question #274 : Evolution And Genetics

Which of the following best represents an example of sexual selection?

Possible Answers:

Selection for brightly colored plumage to attract female birds

Selection for traits that aid in predator avoidance

Selection for antibiotic resistance in microorganisms

Selection for mechanisms that prevent polyspermy

Correct answer:

Selection for brightly colored plumage to attract female birds

Explanation:

Sexual selection is selection for traits that confer greater reproductive success. This includes selection for traits that better attract mates.

Example Question #275 : Evolution And Genetics

Which of the following is not true regarding heterozygote advantage?

Possible Answers:

Heterozygotes have an advantage in the population

An example in humans is sickle cell anemia

Heterozygosity confers lower fitness 

Heterozygosity may confer both advantages and disadvantages

Correct answer:

Heterozygosity confers lower fitness 

Explanation:

The heterozygote advantage is when a heterozygote phenotype increases fitness, as compared to both homozygote phenotypes. An example of this in human populations is sickle cell anemia—a condition where red blood cells cannot properly transport oxygen. Individuals that are heterozygotes are resistant to malaria. The example of sickle cell anemia demonstrates that heterozygosity may confer advantages and disadvantages, but homozygosity only confers a disadvantage.

Example Question #271 : Evolution And Genetics

Which of the following best defines interference competition?

Possible Answers:

Members of the same species compete for the same resources

Direct competition between individuals through aggression

Indirect competition through a limiting resource

Indirect competition between two species hunted by the same predator

Correct answer:

Direct competition between individuals through aggression

Explanation:

Interference competition is a type of competition that occurs directly between individuals through the use of aggression.

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