BIO 182 EXAM 2 ASU 2026 EVOLUTION AND
DIVERSITY DRILL PACK ANSWER SHEET
◉ what does it mean to say that an allele is fixed in the population.
Answer: it is an indication of no genetic variation at that locus in the
population
◉ In a hypothetical population of 1000 frogs there exists a gene with
two alleles. 280 of the frogs are homozygous dominant (DD), and
220 are homozygous recessive (dd). What is the frequency of
heterozygotes in the population?.
Answer: .50
◉ Human ABO blood groups are determined by a single gene with 3
alleles: A, B, and O. In a sample of 300 individuals, 100 are blood
type A and genotype AA, 100 are blood type B and genotype BO, and
100 are blood type O and genotype OO. What are the allele
frequencies?.
Answer: 33.3% A, 16.6% B, 50% O
◉ If the allele frequency for the recessive single allele that causes a
particular rare hair color is 0.02, how frequently would you expect
the hair color to be present in humans?.
Answer: q^2= (.02)^2=.0004= 1 in every 2500 individuals
,◉ the allele frequency of all the alleles of a gene present in the
population must add to 1.
Answer: true
◉ you have a small population of beetles. one day a large rainstorm
causes flooding and wipes out 87% of the population. the remaining
individuals have much lower genetic variation than the original
population. which of the following would explain the lack of hardy-
weinberg equilibrium seen after the flood?.
Answer: genetic drift
◉ the differential success of alleles is called.
Answer: selection
◉ if the frequency of allele A is 0.7, using the hardy-weinberg
formula, what would the frequency of the heterozygous Aa genotype
be?.
Answer: 2(.7)(.3)= .42
◉ hardy-weinberg formula.
Answer: p^2 + 2pq + q^2 = 1
,◉ in new mexico, large expanses of black lava create patches of
unique habitat. if, in every generation, selection favors the darkest
colored pocket mice in those habitats because they are best hidden
from predators ,this would be an example of.
Answer: directional selection
◉ ___ selection is where individuals choose mates based upon the
quality of their appearance and/ or their decorative ornaments.
Answer: sexual
◉ a good example of evolution through natural selection affecting
human health would be.
Answer: a. the spread of antibiotic resistant bacteria in hospitals
b. the progression of metastatic cancer and increasing resistance to
chemotherapy
◉ the allele underlying sickle-cell disease affects the structure of the
___ molecules inside ___ blood cells.
Answer: hemoglobin; red
◉ which researcher was the first to propose the concept of sexual
selection?.
Answer: charles darwin
, ◉ how could something as complex as the behavior of ant-
parasitizing Lomechusa have evolved? these are beetles with special
glands, behavior, and body-shape that trick ants into taking them
into their nests..
Answer: 1. these complex behaviors may have arisen gradually
through natural selection
2. many lomechusa beetles have already pre-existing glands and
behaviors that could potentially be co-opted and modified through
time
◉ which of the following were modified through artificial selection
by humans?
a. dogs
b. cabbages
c. chickens.
Answer: all of the above
◉ why is it that for many animal lineages, we don't see many
transitional fossils?.
Answer: 1. fossilization is chancy and usually only preserves hard
skeletons or exoskeletons
2. more transitional fossils are being discovered
3. it may be that evolution is not always quite so gradual an affair as
charles darwin imagined it to be
DIVERSITY DRILL PACK ANSWER SHEET
◉ what does it mean to say that an allele is fixed in the population.
Answer: it is an indication of no genetic variation at that locus in the
population
◉ In a hypothetical population of 1000 frogs there exists a gene with
two alleles. 280 of the frogs are homozygous dominant (DD), and
220 are homozygous recessive (dd). What is the frequency of
heterozygotes in the population?.
Answer: .50
◉ Human ABO blood groups are determined by a single gene with 3
alleles: A, B, and O. In a sample of 300 individuals, 100 are blood
type A and genotype AA, 100 are blood type B and genotype BO, and
100 are blood type O and genotype OO. What are the allele
frequencies?.
Answer: 33.3% A, 16.6% B, 50% O
◉ If the allele frequency for the recessive single allele that causes a
particular rare hair color is 0.02, how frequently would you expect
the hair color to be present in humans?.
Answer: q^2= (.02)^2=.0004= 1 in every 2500 individuals
,◉ the allele frequency of all the alleles of a gene present in the
population must add to 1.
Answer: true
◉ you have a small population of beetles. one day a large rainstorm
causes flooding and wipes out 87% of the population. the remaining
individuals have much lower genetic variation than the original
population. which of the following would explain the lack of hardy-
weinberg equilibrium seen after the flood?.
Answer: genetic drift
◉ the differential success of alleles is called.
Answer: selection
◉ if the frequency of allele A is 0.7, using the hardy-weinberg
formula, what would the frequency of the heterozygous Aa genotype
be?.
Answer: 2(.7)(.3)= .42
◉ hardy-weinberg formula.
Answer: p^2 + 2pq + q^2 = 1
,◉ in new mexico, large expanses of black lava create patches of
unique habitat. if, in every generation, selection favors the darkest
colored pocket mice in those habitats because they are best hidden
from predators ,this would be an example of.
Answer: directional selection
◉ ___ selection is where individuals choose mates based upon the
quality of their appearance and/ or their decorative ornaments.
Answer: sexual
◉ a good example of evolution through natural selection affecting
human health would be.
Answer: a. the spread of antibiotic resistant bacteria in hospitals
b. the progression of metastatic cancer and increasing resistance to
chemotherapy
◉ the allele underlying sickle-cell disease affects the structure of the
___ molecules inside ___ blood cells.
Answer: hemoglobin; red
◉ which researcher was the first to propose the concept of sexual
selection?.
Answer: charles darwin
, ◉ how could something as complex as the behavior of ant-
parasitizing Lomechusa have evolved? these are beetles with special
glands, behavior, and body-shape that trick ants into taking them
into their nests..
Answer: 1. these complex behaviors may have arisen gradually
through natural selection
2. many lomechusa beetles have already pre-existing glands and
behaviors that could potentially be co-opted and modified through
time
◉ which of the following were modified through artificial selection
by humans?
a. dogs
b. cabbages
c. chickens.
Answer: all of the above
◉ why is it that for many animal lineages, we don't see many
transitional fossils?.
Answer: 1. fossilization is chancy and usually only preserves hard
skeletons or exoskeletons
2. more transitional fossils are being discovered
3. it may be that evolution is not always quite so gradual an affair as
charles darwin imagined it to be
