BIOL 1407 LECTURE EXAM #1
QUESTION BANK WITH CORRECT
ANSWERS
When a population is in Hardy-Weinberg equilibrium: - Correct Answers -No natural
selection is occurring.
Which of the following statements about the reproductive strategies of males and
females is true? - Correct Answers -Males and females often have different reproductive
strategies.
A type of sexual selection in which members of one sex, usually females, choose mates
based on particular characteristics such as courtship songs is called: - Correct Answers
-Intersexual selection.
Select all of the following criteria that must be present for natural selection to occur and
cause evolutionary change in a population. - Correct Answers -Variation must have a
genetic basis
Variation must exist among individuals
Variation must result in differences in the number of offspring surviving in the next
generation
Genetic variation in a population results from evolutionary forces that cause changes in:
- Correct Answers -Allele frequencies.
_________ selection favors individuals with intermediate phenotypes and selects
against individuals with extreme phenotypes. - Correct Answers -Stabilizing.
Changes in allele frequencies within a population may result from _________, which are
changes in the nucleotide sequences of an organism's DNA. - Correct Answers -
Mutations.
Natural populations exhibit significant phenotypic and _________ variation. - Correct
Answers -Genotypic.
For a population to be in Hardy-Weinberg equilibrium: - Correct Answers -There must
be no migration into it out of the population.
,T/F: Within the same species, females and males usually employ the same reproductive
strategy. - Correct Answers -False
Why does selection occur? - Correct Answers -Because some individuals in a
population possess more favorable phenotypes than others.
Which of the following is true of evolutionary forces in natural populations? - Correct
Answers -Evolutionary forces can alter allele frequencies in natural populations.
In natural populations, most genes: - Correct Answers -Exhibit variation.
Select all the conditions that must be met for a population to be in Hardy-Weinberg
equilibrium. - Correct Answers -The population is very large
Mating is random
No new mutations occur
Many 19th century scientists believed that natural selection always favored an optimal
form, and therefore would tend to reduce or eliminate which of the following? - Correct
Answers -Genetic variation.
If we find evidence that a population is experiencing changes in allele frequencies from
one generation to the next, we say that this population is which of the following? -
Correct Answers -Not in Hardy-Weinberg equilibrium.
The processes that lead to evolutionary change are mutations, natural selection,
_______ drift, gene flow and _______ mating. - Correct Answers -Genetic; nonrandom
New mutations are not a major factor affecting the allele frequencies in a population
because: - Correct Answers -The rate at which new mutations occur is low.
What is gene flow? - Correct Answers -The movement of alleles into it out of a
population.
Which evolutionary mechanism changes genotype frequencies but does not change
allele frequencies? - Correct Answers -Assortative mating.
The amount of genetic variation present in naturally occurring populations is: - Correct
Answers -Significant.
What can likely happen to uncommon alleles in small, isolated populations as a result of
genetic drift? - Correct Answers -They are likely to be lost.
_______ is the ultimate source of genetic variation. - Correct Answers -Mutation.
What term quantifies reproductive success of a phenotype? - Correct Answers -Fitness.
, In a population of seahorses, red seahorses on average produce 125 offspring and
brown seahorses produce 75 offspring. What is the fitness of the brown phenotype? -
Correct Answers -0.6.
Choose all the components of fitness from the list below. - Correct Answers -Individual
survival, mating success, and production of viable, numerous offspring.
The sex that is most choosy in selecting a mate is generally the sex that invests the
most energy and time in producing and rearing offspring. Which of the following refers
to the investment of time and energy? - Correct Answers -Parental investment.
Sexual selection is a type of natural selection in which the evolution of certain traits is
driven by which if the following types of competition? - Correct Answers -Competition for
mates.
A deer's antlers, a ram's horns and the bring plumage of a male paradise bird are all
examples of which of the following? - Correct Answers -Secondary sexual
characteristics.
Genetic drift has a greater impact in which of the following? - Correct Answers -Small
populations.
In _________ - _________ selection, the fitness of a phenotype depends on the
proportion of individuals in the population that have that phenotype. - Correct Answers -
Frequency-dependent.
Ground finches with large bills are favored during times of drought, while ground finches
with small bills are favored during times when water is abundant. This is an example of:
- Correct Answers -Oscillating selection.
The term heterozygote _______ refers to situations in which heterozygotes are more fit
than either homozygotes. - Correct Answers -Advantage.
Which type of selection acts to eliminate individuals which are intermediate on a
phenotypic range? - Correct Answers -Disruptive selection.
__________ selection favors individuals at one extreme of a phenotypic range. Those
individuals usually have greater reproductive success in a particular environment. -
Correct Answers -Directional.
What appears to determine variations in the coloration, size and maturation of guppies
in northeastern South American streams? - Correct Answers -The location of streams
relative to waterfalls.
QUESTION BANK WITH CORRECT
ANSWERS
When a population is in Hardy-Weinberg equilibrium: - Correct Answers -No natural
selection is occurring.
Which of the following statements about the reproductive strategies of males and
females is true? - Correct Answers -Males and females often have different reproductive
strategies.
A type of sexual selection in which members of one sex, usually females, choose mates
based on particular characteristics such as courtship songs is called: - Correct Answers
-Intersexual selection.
Select all of the following criteria that must be present for natural selection to occur and
cause evolutionary change in a population. - Correct Answers -Variation must have a
genetic basis
Variation must exist among individuals
Variation must result in differences in the number of offspring surviving in the next
generation
Genetic variation in a population results from evolutionary forces that cause changes in:
- Correct Answers -Allele frequencies.
_________ selection favors individuals with intermediate phenotypes and selects
against individuals with extreme phenotypes. - Correct Answers -Stabilizing.
Changes in allele frequencies within a population may result from _________, which are
changes in the nucleotide sequences of an organism's DNA. - Correct Answers -
Mutations.
Natural populations exhibit significant phenotypic and _________ variation. - Correct
Answers -Genotypic.
For a population to be in Hardy-Weinberg equilibrium: - Correct Answers -There must
be no migration into it out of the population.
,T/F: Within the same species, females and males usually employ the same reproductive
strategy. - Correct Answers -False
Why does selection occur? - Correct Answers -Because some individuals in a
population possess more favorable phenotypes than others.
Which of the following is true of evolutionary forces in natural populations? - Correct
Answers -Evolutionary forces can alter allele frequencies in natural populations.
In natural populations, most genes: - Correct Answers -Exhibit variation.
Select all the conditions that must be met for a population to be in Hardy-Weinberg
equilibrium. - Correct Answers -The population is very large
Mating is random
No new mutations occur
Many 19th century scientists believed that natural selection always favored an optimal
form, and therefore would tend to reduce or eliminate which of the following? - Correct
Answers -Genetic variation.
If we find evidence that a population is experiencing changes in allele frequencies from
one generation to the next, we say that this population is which of the following? -
Correct Answers -Not in Hardy-Weinberg equilibrium.
The processes that lead to evolutionary change are mutations, natural selection,
_______ drift, gene flow and _______ mating. - Correct Answers -Genetic; nonrandom
New mutations are not a major factor affecting the allele frequencies in a population
because: - Correct Answers -The rate at which new mutations occur is low.
What is gene flow? - Correct Answers -The movement of alleles into it out of a
population.
Which evolutionary mechanism changes genotype frequencies but does not change
allele frequencies? - Correct Answers -Assortative mating.
The amount of genetic variation present in naturally occurring populations is: - Correct
Answers -Significant.
What can likely happen to uncommon alleles in small, isolated populations as a result of
genetic drift? - Correct Answers -They are likely to be lost.
_______ is the ultimate source of genetic variation. - Correct Answers -Mutation.
What term quantifies reproductive success of a phenotype? - Correct Answers -Fitness.
, In a population of seahorses, red seahorses on average produce 125 offspring and
brown seahorses produce 75 offspring. What is the fitness of the brown phenotype? -
Correct Answers -0.6.
Choose all the components of fitness from the list below. - Correct Answers -Individual
survival, mating success, and production of viable, numerous offspring.
The sex that is most choosy in selecting a mate is generally the sex that invests the
most energy and time in producing and rearing offspring. Which of the following refers
to the investment of time and energy? - Correct Answers -Parental investment.
Sexual selection is a type of natural selection in which the evolution of certain traits is
driven by which if the following types of competition? - Correct Answers -Competition for
mates.
A deer's antlers, a ram's horns and the bring plumage of a male paradise bird are all
examples of which of the following? - Correct Answers -Secondary sexual
characteristics.
Genetic drift has a greater impact in which of the following? - Correct Answers -Small
populations.
In _________ - _________ selection, the fitness of a phenotype depends on the
proportion of individuals in the population that have that phenotype. - Correct Answers -
Frequency-dependent.
Ground finches with large bills are favored during times of drought, while ground finches
with small bills are favored during times when water is abundant. This is an example of:
- Correct Answers -Oscillating selection.
The term heterozygote _______ refers to situations in which heterozygotes are more fit
than either homozygotes. - Correct Answers -Advantage.
Which type of selection acts to eliminate individuals which are intermediate on a
phenotypic range? - Correct Answers -Disruptive selection.
__________ selection favors individuals at one extreme of a phenotypic range. Those
individuals usually have greater reproductive success in a particular environment. -
Correct Answers -Directional.
What appears to determine variations in the coloration, size and maturation of guppies
in northeastern South American streams? - Correct Answers -The location of streams
relative to waterfalls.
