BIO 182 EXAM 2 QUESTIONS AND
ANSWERS WITH SOLUTIONS 2024
Which of these individuals has the highest biological fitness in an evolutionary sense? - ANSWER an
organism that dies after 5 days of life but leaves 10 offspring, all of whom survive to reproduce
True or False: The genotype of an organism describes the physical traits that one can observe. - ANSWER
False
Which of the following statement(s) regarding evolutionary adaptation is/are true? Select ALL that apply.
- ANSWER - A trait that is adaptive in one environment may not be adaptive in a different environment.
- The adaptive value of a trait can change over time as the environment changes.
What are the core principles necessary for natural selection to occur in a population? Select ALL that
apply. - ANSWER - Traits need to be passed on from parents to offspring
- There needs to be variation in a population
- Some organisms have a higher reproductive success than others
Evolution of a new trait typically takes many generations. Yet a dramatic shift in the extent of armor
plating in the Lake Washington stickleback population occurred in the 50 years following the cleanup of
the lake. Which of the following best describes the mechanism of the rapid evolution of the armor
phenotype in the Lake Washington sticklebacks? - ANSWER New selective pressures favored individuals
with the plated phenotype, causing the plated allele frequency in the population to quickly increase.
True or False: Sexual selection is a case of natural selection that describes evolution due not to variable
survival rates, but rather due to variable reproductive rates stemming from characteristics that allow an
individual to successfully attract a mate. - ANSWER True
In the northeastern United States and adjacent Canada, there has been intense industrial fishing for
large predatory fishes, such as Atlantic Cod. Prior to industrial fishing, the relationship between the size
of a fish at maturity and its fitness is shown by the graph on the left (below). Fishing is size-selective,
with fishers generally taking the largest fish. The fitness function during industrial fishing is reflected in
the graph on the right (below).
, Based on this information, which of the following is true about the selection for size at maturity? -
ANSWER Cod experienced balancing selection before industrial fishing, but now experience directional
selection.
A new plant population develops the ability to grow on high-zinc-soil and can do so at concentrations
which are otherwise lethal to plants of the same species. This is an example of ___________ selection: -
ANSWER Directional
A farmer sprays insecticides on her crops to successfully get rid of weevils, a beetle pest. After a few
years of spraying the insecticide, she finds that weevils are becoming more and more common again.
What is the most likely explanation for this? Select only ONE answer choice. - ANSWER Weevils that are
resistant to the insecticide are favoured by natural selection over weevils that are susceptible to the
insecticide.
According to the biological species concept, the main criterion for identifying a species is: - ANSWER
reproductive isolation
Which of the following statements is/are correct? - ANSWER A population is a local subset of a species.
Which of the following is/are a criticism(s) of the usefulness of the biological species concept? - ANSWER
B & C only
- It is difficult to tell whether two individuals are actually or potentially capable of producing fertile
offspring in the field.
- Some species only reproduce asexually.
You collect individuals from different allopatric populations of a leaf-eating beetle. In the laboratory, you
conduct mate-choice experiments to assess levels of reproductive isolation among beetles from different
populations.
True or False: In order to determine if these different populations are different species based in the
biological species concept, you would need to find information indicating complete reproductive
isolation among all of the populations. - ANSWER true
A defining characteristic of allopatric speciation is: - ANSWER geographic isolation
ANSWERS WITH SOLUTIONS 2024
Which of these individuals has the highest biological fitness in an evolutionary sense? - ANSWER an
organism that dies after 5 days of life but leaves 10 offspring, all of whom survive to reproduce
True or False: The genotype of an organism describes the physical traits that one can observe. - ANSWER
False
Which of the following statement(s) regarding evolutionary adaptation is/are true? Select ALL that apply.
- ANSWER - A trait that is adaptive in one environment may not be adaptive in a different environment.
- The adaptive value of a trait can change over time as the environment changes.
What are the core principles necessary for natural selection to occur in a population? Select ALL that
apply. - ANSWER - Traits need to be passed on from parents to offspring
- There needs to be variation in a population
- Some organisms have a higher reproductive success than others
Evolution of a new trait typically takes many generations. Yet a dramatic shift in the extent of armor
plating in the Lake Washington stickleback population occurred in the 50 years following the cleanup of
the lake. Which of the following best describes the mechanism of the rapid evolution of the armor
phenotype in the Lake Washington sticklebacks? - ANSWER New selective pressures favored individuals
with the plated phenotype, causing the plated allele frequency in the population to quickly increase.
True or False: Sexual selection is a case of natural selection that describes evolution due not to variable
survival rates, but rather due to variable reproductive rates stemming from characteristics that allow an
individual to successfully attract a mate. - ANSWER True
In the northeastern United States and adjacent Canada, there has been intense industrial fishing for
large predatory fishes, such as Atlantic Cod. Prior to industrial fishing, the relationship between the size
of a fish at maturity and its fitness is shown by the graph on the left (below). Fishing is size-selective,
with fishers generally taking the largest fish. The fitness function during industrial fishing is reflected in
the graph on the right (below).
, Based on this information, which of the following is true about the selection for size at maturity? -
ANSWER Cod experienced balancing selection before industrial fishing, but now experience directional
selection.
A new plant population develops the ability to grow on high-zinc-soil and can do so at concentrations
which are otherwise lethal to plants of the same species. This is an example of ___________ selection: -
ANSWER Directional
A farmer sprays insecticides on her crops to successfully get rid of weevils, a beetle pest. After a few
years of spraying the insecticide, she finds that weevils are becoming more and more common again.
What is the most likely explanation for this? Select only ONE answer choice. - ANSWER Weevils that are
resistant to the insecticide are favoured by natural selection over weevils that are susceptible to the
insecticide.
According to the biological species concept, the main criterion for identifying a species is: - ANSWER
reproductive isolation
Which of the following statements is/are correct? - ANSWER A population is a local subset of a species.
Which of the following is/are a criticism(s) of the usefulness of the biological species concept? - ANSWER
B & C only
- It is difficult to tell whether two individuals are actually or potentially capable of producing fertile
offspring in the field.
- Some species only reproduce asexually.
You collect individuals from different allopatric populations of a leaf-eating beetle. In the laboratory, you
conduct mate-choice experiments to assess levels of reproductive isolation among beetles from different
populations.
True or False: In order to determine if these different populations are different species based in the
biological species concept, you would need to find information indicating complete reproductive
isolation among all of the populations. - ANSWER true
A defining characteristic of allopatric speciation is: - ANSWER geographic isolation
