PCB 3043 Chapter 9 Exam Questions with Correct Answers Latest Update 2025/2026
Classify the statement about asexual and sexual reproduction as true or false:
Offspring may be produced from vegetative tissues of the parent in asexual reproduction. -
Answers True
Classify the statement about asexual and sexual reproduction as true or false:
Harmful alleles may only be inherited by some offspring during sexual reproduction. - Answers
True
Classify the statement about asexual and sexual reproduction as true or false:
Individuals may engage in costly or risky social behavior when reproducing sexually. - Answers
True
Classify the statement about asexual and sexual reproduction as true or false:
Hermaphroditic organisms may self-fertilize to reproduce asexually or cross-fertilize to
reproduce sexually. - Answers False
Classify the statement about asexual and sexual reproduction as true or false:
On average, siblings produced asexually share about 50% of their DNA sequence with each
other. - Answers False
Classify the statement about asexual and sexual reproduction as true or false:
A diploid parent always passes on two copies of its genes to its offspring during sexual
reproduction. - Answers False
How does the Red Queen hypothesis explain a fitness benefit of sexual reproduction?
-Sexually reproducing organisms carefully choose their partners, so only the fittest individuals
, mate and produce high quality offspring.
-Offspring produced by sexual reproduction are less likely to inherit rare genetic disorders than
offspring produced by asexual reproduction.
-Species that use sexual reproduction live longer and produce more offspring than species that
reproduce asexually.
-Sexual reproduction produces genetic variation that allows some offspring to survive evolving
parasites. - Answers -Sexual reproduction produces genetic variation that allows some offspring
to survive evolving parasites.
Some species of freshwater snails can reproduce both sexually and asexually, but asexual
reproduction yields more offspring. Identify the condition that favors sexual reproduction.
-Small population size.
-Heavily skewed sex ratio.
-High parasite abundance.
-Abundant food supply. - Answers -High parasite abundance.
Identify the conditions that favor self-fertilization over outcrossing in a hermaphroditic plant
species.
-Small population size.
-High herbivore activity.
-High pollinator activity.
-Rapid climate change. - Answers -Small population size.
-High herbivore activity.
What adaptations have evolved in plants that would help monoecious plants prevent inbreeding?
-Male and female gametes produced by the same plant have different number of chromosomes.
-Self-incompatibility genes prevent an individual from mating with itself.
-The plants produce many more female flowers than male gametes to ensure some amount of
Classify the statement about asexual and sexual reproduction as true or false:
Offspring may be produced from vegetative tissues of the parent in asexual reproduction. -
Answers True
Classify the statement about asexual and sexual reproduction as true or false:
Harmful alleles may only be inherited by some offspring during sexual reproduction. - Answers
True
Classify the statement about asexual and sexual reproduction as true or false:
Individuals may engage in costly or risky social behavior when reproducing sexually. - Answers
True
Classify the statement about asexual and sexual reproduction as true or false:
Hermaphroditic organisms may self-fertilize to reproduce asexually or cross-fertilize to
reproduce sexually. - Answers False
Classify the statement about asexual and sexual reproduction as true or false:
On average, siblings produced asexually share about 50% of their DNA sequence with each
other. - Answers False
Classify the statement about asexual and sexual reproduction as true or false:
A diploid parent always passes on two copies of its genes to its offspring during sexual
reproduction. - Answers False
How does the Red Queen hypothesis explain a fitness benefit of sexual reproduction?
-Sexually reproducing organisms carefully choose their partners, so only the fittest individuals
, mate and produce high quality offspring.
-Offspring produced by sexual reproduction are less likely to inherit rare genetic disorders than
offspring produced by asexual reproduction.
-Species that use sexual reproduction live longer and produce more offspring than species that
reproduce asexually.
-Sexual reproduction produces genetic variation that allows some offspring to survive evolving
parasites. - Answers -Sexual reproduction produces genetic variation that allows some offspring
to survive evolving parasites.
Some species of freshwater snails can reproduce both sexually and asexually, but asexual
reproduction yields more offspring. Identify the condition that favors sexual reproduction.
-Small population size.
-Heavily skewed sex ratio.
-High parasite abundance.
-Abundant food supply. - Answers -High parasite abundance.
Identify the conditions that favor self-fertilization over outcrossing in a hermaphroditic plant
species.
-Small population size.
-High herbivore activity.
-High pollinator activity.
-Rapid climate change. - Answers -Small population size.
-High herbivore activity.
What adaptations have evolved in plants that would help monoecious plants prevent inbreeding?
-Male and female gametes produced by the same plant have different number of chromosomes.
-Self-incompatibility genes prevent an individual from mating with itself.
-The plants produce many more female flowers than male gametes to ensure some amount of
