Bio 150 Final Exam - UTK Mamantov Questions and 100%
correct answers |Graded A+ (2026/2027)
Cystic Fibrosis (recessive trait) affects approximately 1 in 2000 individuals of European descent.
Assuming the population is in equilibrium, what is the frequency of the recessive allele in the
population?
A. 0.0005
B. 0.022
C. 0.043
D. 0.978 - Answer -B. 0.022
Tay-Sachs is a recessive trait. Among Ashkenazi Jews of central European ancestry, about 1 in
3,600 children is born with the disease. What percent of individuals in this population are
carriers (heterozygous genotype)?
A. 1.7%
B. 2.9%
C. 3.3%
D. 98.2% - Answer -C. 3.3%
In the process of transcription, ________.
A. mRNA attaches to ribosomes
B. RNA is synthesized
C. Proteins are synthesized
D. DNA is replicated - Answer -B. RNA is synthesized
1|Page
,In analyzing the number of different bases in a DNA sample, which result would be consistent
with the base-pairing rules?
A. A/T = C/G
B. A = G
C. A + T = G + T
D. G = T
E. C = A - Answer -A. A/T = C/G
A population of the endangered Tennessee cone flower consists of 15 individuals. There are two
alleles in the population that determine the alcohol dehydrogenase enzyme: adh1 and adh2
10 adh1 adh1 homozygotes
1 adh1 adh2 heterozygote
4 adh2 adh2 homozygotes
What is the frequency of the adh1 allele? - Answer -70%
If p = 0.7, what is the expected frequency of the homozygous recessive genotype if the
population is in Hardy-Weinberg equilibrium?
*Assume p is the frequency of the dominant allele
A. 0.01
B. 0.09
C. 0.42
D. 0.49
2|Page
,E. 0.63 - Answer -B. 0.09
Examine the following population. Has evolution occurred?
Gene A has two alleles: "A" is dominant over "a".
Start: population consists of 4 AA, 8 Aa, and 3 aa individuals
End: population consists of 1 AA, 14 Aa, and 0 aa individuals - Answer -No, allele frequencies
haven't changed
Which of the following questions about dung beetles would be studied at the population level
of biological organization?
A. How do dung beetles of different species compete for access to dung food sources?
B. What gene is responsible for determining the horn phenotype in the dung beetle species, O.
taurus?
C. How does the recycling of dung by beetles impact the carbon cycle on cattle fields?
D. How does the percentage of horned males vary in O. taurus beetles living in different
geographic areas? - Answer -D. How does the percentage of horned males vary in O. taurus
beetles living in different geographic areas?
When an organism is better able to survive in an environment due to a new mutation we can
conclude:
A. the mutation occurred in response to the environment in order to improve survivorship
B. this could not happen; mutations are always deleterious
C. the mutation occurred at random with respect to the phenotypic change it caused
D. the mutation must have been a chromosomal insertion - Answer -C. the mutation occurred at
random with respect to the phenotypic change it caused
3|Page
, For biologists studying a large flatworm population in the lab, which of the following Hardy-
Weinberg conditions is most difficult to meet?
A. No genetic drift
B. No gene flow
C. No mutation
D. Random mating - Answer -C. No mutation
When nonrandom mating occurs in a population so that individuals prefer to mate with similar
individuals, allele frequencies should:
A. remain the same, but homozygotes will be overrepresented in the population
B. remain the same, but heterozygotes will be overrepresented in the population.
C. change and heterozygotes will be overrepresented in the population
D. change and homozygotes will be overrepresented in the population.
E. remain the same, and genotype frequencies remain at Hardy-Weinberg equilibrium. - Answer
-A. remain the same, but homozygotes will be overrepresented in the population
The Dunkers are a religious group that moved from Germany to Pennsylvania in the mid 1700s.
They do not marry members outside their own immediate community. Today, the Dunkers are
genetically unique and differ in gene frequencies, at many loci, from all other populations,
including those in their original homeland. Which of the following likely explains the genetic
uniqueness of this population?
A. Population bottleneck and Hardy-Weinberg equilibrium
B. Gene flow and inbreeding depression
C. Mutation
4|Page
correct answers |Graded A+ (2026/2027)
Cystic Fibrosis (recessive trait) affects approximately 1 in 2000 individuals of European descent.
Assuming the population is in equilibrium, what is the frequency of the recessive allele in the
population?
A. 0.0005
B. 0.022
C. 0.043
D. 0.978 - Answer -B. 0.022
Tay-Sachs is a recessive trait. Among Ashkenazi Jews of central European ancestry, about 1 in
3,600 children is born with the disease. What percent of individuals in this population are
carriers (heterozygous genotype)?
A. 1.7%
B. 2.9%
C. 3.3%
D. 98.2% - Answer -C. 3.3%
In the process of transcription, ________.
A. mRNA attaches to ribosomes
B. RNA is synthesized
C. Proteins are synthesized
D. DNA is replicated - Answer -B. RNA is synthesized
1|Page
,In analyzing the number of different bases in a DNA sample, which result would be consistent
with the base-pairing rules?
A. A/T = C/G
B. A = G
C. A + T = G + T
D. G = T
E. C = A - Answer -A. A/T = C/G
A population of the endangered Tennessee cone flower consists of 15 individuals. There are two
alleles in the population that determine the alcohol dehydrogenase enzyme: adh1 and adh2
10 adh1 adh1 homozygotes
1 adh1 adh2 heterozygote
4 adh2 adh2 homozygotes
What is the frequency of the adh1 allele? - Answer -70%
If p = 0.7, what is the expected frequency of the homozygous recessive genotype if the
population is in Hardy-Weinberg equilibrium?
*Assume p is the frequency of the dominant allele
A. 0.01
B. 0.09
C. 0.42
D. 0.49
2|Page
,E. 0.63 - Answer -B. 0.09
Examine the following population. Has evolution occurred?
Gene A has two alleles: "A" is dominant over "a".
Start: population consists of 4 AA, 8 Aa, and 3 aa individuals
End: population consists of 1 AA, 14 Aa, and 0 aa individuals - Answer -No, allele frequencies
haven't changed
Which of the following questions about dung beetles would be studied at the population level
of biological organization?
A. How do dung beetles of different species compete for access to dung food sources?
B. What gene is responsible for determining the horn phenotype in the dung beetle species, O.
taurus?
C. How does the recycling of dung by beetles impact the carbon cycle on cattle fields?
D. How does the percentage of horned males vary in O. taurus beetles living in different
geographic areas? - Answer -D. How does the percentage of horned males vary in O. taurus
beetles living in different geographic areas?
When an organism is better able to survive in an environment due to a new mutation we can
conclude:
A. the mutation occurred in response to the environment in order to improve survivorship
B. this could not happen; mutations are always deleterious
C. the mutation occurred at random with respect to the phenotypic change it caused
D. the mutation must have been a chromosomal insertion - Answer -C. the mutation occurred at
random with respect to the phenotypic change it caused
3|Page
, For biologists studying a large flatworm population in the lab, which of the following Hardy-
Weinberg conditions is most difficult to meet?
A. No genetic drift
B. No gene flow
C. No mutation
D. Random mating - Answer -C. No mutation
When nonrandom mating occurs in a population so that individuals prefer to mate with similar
individuals, allele frequencies should:
A. remain the same, but homozygotes will be overrepresented in the population
B. remain the same, but heterozygotes will be overrepresented in the population.
C. change and heterozygotes will be overrepresented in the population
D. change and homozygotes will be overrepresented in the population.
E. remain the same, and genotype frequencies remain at Hardy-Weinberg equilibrium. - Answer
-A. remain the same, but homozygotes will be overrepresented in the population
The Dunkers are a religious group that moved from Germany to Pennsylvania in the mid 1700s.
They do not marry members outside their own immediate community. Today, the Dunkers are
genetically unique and differ in gene frequencies, at many loci, from all other populations,
including those in their original homeland. Which of the following likely explains the genetic
uniqueness of this population?
A. Population bottleneck and Hardy-Weinberg equilibrium
B. Gene flow and inbreeding depression
C. Mutation
4|Page
