BIO 182 Exam 2 Questions with
Accurate Answers
Which of these individuals has the highest biological fitness in an evolutionary sense? -
ANSWERSan 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. - ANSWERSFalse
Which of the following statement(s) regarding evolutionary adaptation is/are true?
Select ALL that apply. - ANSWERS- 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. - ANSWERS- 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? - ANSWERSNew 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. -
ANSWERSTrue
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? - ANSWERSCod 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: - ANSWERSDirectional
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. - ANSWERSWeevils 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: - ANSWERSreproductive isolation
Which of the following statements is/are correct? - ANSWERSA 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? - ANSWERSB & 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. - ANSWERStrue
A defining characteristic of allopatric speciation is: - ANSWERSgeographic isolation
Continuous desert tortoise populations across the Sonoran desert have adapted to
different climates, where the climate near the northern edge of the Sonoran desert is
extremely hot and dry, while the climate near the southern edge has more scrub, shade,
and access to water. Evidence suggests that there are now two species of desert
tortoises. True or False: This is an example of Allopatric speciation. - ANSWERSfalse
Which of the following is an example of allopatric speciation? - ANSWERSEvolution of
genetic reproductive barriers between populations of angelfish isolated on either side of
the Isthmus of Panama
Accurate Answers
Which of these individuals has the highest biological fitness in an evolutionary sense? -
ANSWERSan 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. - ANSWERSFalse
Which of the following statement(s) regarding evolutionary adaptation is/are true?
Select ALL that apply. - ANSWERS- 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. - ANSWERS- 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? - ANSWERSNew 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. -
ANSWERSTrue
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? - ANSWERSCod 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: - ANSWERSDirectional
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. - ANSWERSWeevils 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: - ANSWERSreproductive isolation
Which of the following statements is/are correct? - ANSWERSA 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? - ANSWERSB & 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. - ANSWERStrue
A defining characteristic of allopatric speciation is: - ANSWERSgeographic isolation
Continuous desert tortoise populations across the Sonoran desert have adapted to
different climates, where the climate near the northern edge of the Sonoran desert is
extremely hot and dry, while the climate near the southern edge has more scrub, shade,
and access to water. Evidence suggests that there are now two species of desert
tortoises. True or False: This is an example of Allopatric speciation. - ANSWERSfalse
Which of the following is an example of allopatric speciation? - ANSWERSEvolution of
genetic reproductive barriers between populations of angelfish isolated on either side of
the Isthmus of Panama
