BIO 250 Exam 2 — Exam Questions with
Correct Answers (VerifiedAnswers) Plus
Rationales 2026 Q&A Instant Download PDF
Question 1
Which statement best defines relative fitness in an evolutionary
context?
A. The physical strength of an organism compared with
members of another species
B. The ability of an organism to survive regardless of whether it
reproduces
C. The reproductive contribution of an individual or genotype
relative to others in the population
D. The maximum age an organism can reach
Answer: C. The reproductive contribution of an individual or
genotype relative to others in the population
Relative fitness is fundamentally a measure of reproductive
success in comparison with other individuals or genotypes in the
same population. An organism can survive for a long time but
have low fitness if it produces few viable offspring. Conversely,
an individual with a shorter lifespan can have high fitness if it
,successfully produces many surviving offspring that contribute
genes to subsequent generations.
Question 2
Which of the following is most directly required for natural
selection to produce evolutionary change?
A. All individuals must have identical traits
B. Heritable variation must exist among individuals
C. Every individual must reproduce at exactly the same rate
D. Mutations must always be beneficial
Answer: B. Heritable variation must exist among individuals
Natural selection requires variation among individuals,
differences in reproductive success associated with that
variation, and a heritable component to the traits involved. If a
trait is not heritable, differences in the trait cannot reliably be
transmitted to offspring. Mutations may be beneficial, harmful,
or neutral; natural selection does not require mutations to be
beneficial.
Question 3
Which situation represents an obstacle to survival rather than
an obstacle specifically associated with reproduction?
,A. Finding a mate
B. Producing gametes
C. Caring for offspring
D. Avoiding predators
Answer: D. Avoiding predators
Avoiding predators is a direct survival challenge because an
individual must remain alive before it can reproduce. Finding a
mate, producing reproductive cells, and caring for offspring are
associated more directly with reproductive success. Selection
can act on traits that improve survival, reproduction, or both.
Question 4
What is meant by a putative adaptation?
A. A trait proven experimentally to increase fitness in every
environment
B. A trait believed to be an adaptation but requiring further
evidence
C. A trait that decreases reproductive success
D. A trait produced only by artificial selection
Answer: B. A trait believed to be an adaptation but requiring
further evidence
The word “putative” indicates that an explanation is proposed
but has not been sufficiently demonstrated. A trait should not
, automatically be labeled an adaptation simply because it
appears useful. Scientists generally seek evidence showing that
the trait arose through evolutionary processes and contributes
to fitness under relevant environmental conditions.
Question 5
Which statement best describes fecundity?
A. The probability of surviving to adulthood
B. The ability or capacity to reproduce
C. The number of predators encountered during life
D. The age at which an organism dies
Answer: B. The ability or capacity to reproduce
Fecundity refers broadly to reproductive capacity or potential. It
should be distinguished from fertility, which is often used to
describe actual reproductive output or the number of offspring
produced by a reproductive individual. In population ecology,
reproductive terminology helps researchers describe how
populations change over time.
Question 6
Which statement most accurately describes fertility?
Correct Answers (VerifiedAnswers) Plus
Rationales 2026 Q&A Instant Download PDF
Question 1
Which statement best defines relative fitness in an evolutionary
context?
A. The physical strength of an organism compared with
members of another species
B. The ability of an organism to survive regardless of whether it
reproduces
C. The reproductive contribution of an individual or genotype
relative to others in the population
D. The maximum age an organism can reach
Answer: C. The reproductive contribution of an individual or
genotype relative to others in the population
Relative fitness is fundamentally a measure of reproductive
success in comparison with other individuals or genotypes in the
same population. An organism can survive for a long time but
have low fitness if it produces few viable offspring. Conversely,
an individual with a shorter lifespan can have high fitness if it
,successfully produces many surviving offspring that contribute
genes to subsequent generations.
Question 2
Which of the following is most directly required for natural
selection to produce evolutionary change?
A. All individuals must have identical traits
B. Heritable variation must exist among individuals
C. Every individual must reproduce at exactly the same rate
D. Mutations must always be beneficial
Answer: B. Heritable variation must exist among individuals
Natural selection requires variation among individuals,
differences in reproductive success associated with that
variation, and a heritable component to the traits involved. If a
trait is not heritable, differences in the trait cannot reliably be
transmitted to offspring. Mutations may be beneficial, harmful,
or neutral; natural selection does not require mutations to be
beneficial.
Question 3
Which situation represents an obstacle to survival rather than
an obstacle specifically associated with reproduction?
,A. Finding a mate
B. Producing gametes
C. Caring for offspring
D. Avoiding predators
Answer: D. Avoiding predators
Avoiding predators is a direct survival challenge because an
individual must remain alive before it can reproduce. Finding a
mate, producing reproductive cells, and caring for offspring are
associated more directly with reproductive success. Selection
can act on traits that improve survival, reproduction, or both.
Question 4
What is meant by a putative adaptation?
A. A trait proven experimentally to increase fitness in every
environment
B. A trait believed to be an adaptation but requiring further
evidence
C. A trait that decreases reproductive success
D. A trait produced only by artificial selection
Answer: B. A trait believed to be an adaptation but requiring
further evidence
The word “putative” indicates that an explanation is proposed
but has not been sufficiently demonstrated. A trait should not
, automatically be labeled an adaptation simply because it
appears useful. Scientists generally seek evidence showing that
the trait arose through evolutionary processes and contributes
to fitness under relevant environmental conditions.
Question 5
Which statement best describes fecundity?
A. The probability of surviving to adulthood
B. The ability or capacity to reproduce
C. The number of predators encountered during life
D. The age at which an organism dies
Answer: B. The ability or capacity to reproduce
Fecundity refers broadly to reproductive capacity or potential. It
should be distinguished from fertility, which is often used to
describe actual reproductive output or the number of offspring
produced by a reproductive individual. In population ecology,
reproductive terminology helps researchers describe how
populations change over time.
Question 6
Which statement most accurately describes fertility?
