AP BIOLOGY Chapter 23 Exam
Questions and Answers
What is the importance of neutral variation in evolution? - Answer- Neutral variation
increases genetic variation, allowing a population to carry more alleles that may help it
respond to environmental change.
Selection that acts over evolutionary time to preserve traits that increase an individual's
ability to mate is known as _____. - Answer- sexual selection
Which statement below is true about sexual selection? - Answer- Sexual selection can
result in sexual dimorphism—marked differences between the sexes in secondary
sexual characteristics that are not associated directly with reproduction.
How does natural selection fashion organisms? - Answer- Chance and the environment
interact with natural selection, so that the best available traits are selected for.
Natural selection changes allele frequencies because some _______ survive and
reproduce more successfully than others. - Answer- individuals
No two people are genetically identical, except for identical twins. The main source of
genetic variation among human individuals is - Answer- the reshuffling of alleles in
sexual reproduction.
Sparrows with average-sized wings survive severe storms better than those with longer
or shorter wings, illustrating - Answer- stabilizing selection.
If the nucleotide variability of a locus equals 0%, what is the gene variability and number
of alleles at that locus? - Answer- gene variability = 0%; number of alleles = 1
There are 40 individuals in population 1, all with genotype A1A1, and there are 25
individuals in population 2, all with genotype A2A2. Assume that these populations are
located far from each other and that their environmental conditions are very similar.
Based on the information given here, the observed genetic variation is most likely an
example of - Answer- genetic drift.
In the context of populations, how do we define evolution? - Answer- Evolution is a
change in a population's allele frequencies over generations.
Questions and Answers
What is the importance of neutral variation in evolution? - Answer- Neutral variation
increases genetic variation, allowing a population to carry more alleles that may help it
respond to environmental change.
Selection that acts over evolutionary time to preserve traits that increase an individual's
ability to mate is known as _____. - Answer- sexual selection
Which statement below is true about sexual selection? - Answer- Sexual selection can
result in sexual dimorphism—marked differences between the sexes in secondary
sexual characteristics that are not associated directly with reproduction.
How does natural selection fashion organisms? - Answer- Chance and the environment
interact with natural selection, so that the best available traits are selected for.
Natural selection changes allele frequencies because some _______ survive and
reproduce more successfully than others. - Answer- individuals
No two people are genetically identical, except for identical twins. The main source of
genetic variation among human individuals is - Answer- the reshuffling of alleles in
sexual reproduction.
Sparrows with average-sized wings survive severe storms better than those with longer
or shorter wings, illustrating - Answer- stabilizing selection.
If the nucleotide variability of a locus equals 0%, what is the gene variability and number
of alleles at that locus? - Answer- gene variability = 0%; number of alleles = 1
There are 40 individuals in population 1, all with genotype A1A1, and there are 25
individuals in population 2, all with genotype A2A2. Assume that these populations are
located far from each other and that their environmental conditions are very similar.
Based on the information given here, the observed genetic variation is most likely an
example of - Answer- genetic drift.
In the context of populations, how do we define evolution? - Answer- Evolution is a
change in a population's allele frequencies over generations.
