Genetics Exam 1 UPDATED ACTUAL
Exam Questions and CORRECT Answers
For the following two questions, consider the following double-stranded DNA sequence:
5'-ATCATGCCATG-3'
3'-TAGTACGGTAC-5'
1) How many hydrogen bonds are represented in this double helix?
A) 16 B) 9 C) 20 D) 27 E) 8 - CORRECT ANSWER -D
5'-ATCATGCCATG-3'
3'-TAGTACGGTAC-5'
2) How many phosphodiester bonds are represented in this double helix?
A) 9 B) 23 C) 8 D) 20 E) 16 - CORRECT ANSWER -D
aa Bb Cc DD Ee FF
3) How many different gametes can this individual produce?
A) 10 B) 6 C) 12 D) 8 E) 24 - CORRECT ANSWER -D
4) Suppose only one of the gametes is randomly selected. What is the probability that the gamete
with the following combination of alleles is selected?
abCDeF
A) 1/12 B) 1/24 C) 1/8 D) 1/4 E) 1/6 - CORRECT ANSWER -C
5) InDrosophila virilis, nuclei of somatic cells contain 12 chromosomes while nuclei of sperm
cells
contain only 6 chromosomes. What does "n" equal for this species?
A) 12
B) 24
,C) 3
D) 6 or 12, depending on cell type
E) 6 - CORRECT ANSWER -E
6) Which evolutionary process relies on the premises that individuals with the best adaptations
are
most successful at reproducing and leave more offspring than those with less adaptive forms
and that those adaptations have genetic basis?
A) migration
B) natural selection
C) mutation
D) population genetics
E) random genetic drift - CORRECT ANSWER -B
7) Consider a cross between two individuals with the following genotypes at three traits that
assort
independently:
Rr Ss TT x rr Ss Tt
What is the probability that an offspring will be R/r; s/s; T/T?
A) 5/8 B) 1/16 C) 1/4 D) 1/8 E) 3/8 - CORRECT ANSWER -B
8) Consider the cross of the previous question , and assume all capital alleles are dominant. What
is
the probability of having an offspring that shows all the dominant traits?
A) 3/4 B) 3/8 C) 1/4 D) 1/8 E) 3/16 - CORRECT ANSWER -B
9) Mutations at theRb gene lead to dominant cancer that has incomplete penetrance. How is the
penetrance explained?
A) Cancer will develop in Rb+Rb- individuals when cells become homozygoues for the Rballele
, after rare mitotic recombination events.
B) Penetrance is due to the interaction with the environment.
C) Rb-Rb- is lethal
D) Incomplete penetrance is due to interactions with other genes.
E) There is codominance. - CORRECT ANSWER -A
10) Crossingover involves the breakage and reunion of DNA molecules from...
A) non-homologous nonsister chromatids
B) homologous sister chromatids
C) None of the choices are correct
D) non-homologous sister chromatids
E) homologous nonsister chromatid - CORRECT ANSWER -E
11) If you are a male, your X chromosome contains genes derived from...
A) both your paternal grandfather and grandmother
B) your maternal grandfather only
C) both your paternal and maternal grandfathers
D) both your maternal grandfather and grandmother
E) your paternal grandfather only - CORRECT ANSWER -D
12) If genes assort independently, a testcrossed dihybrid characteristically produces progeny
phenotypes in the ratio ...
A) 9:3:3:1 B) 3:1 C) 1:1:1:1 D) 1:1 E) 1:2:1 - CORRECT ANSWER -C
13) Suppose you were investigating a seed color trait determined by a single locus: green versus
brown. When you performed the first cross between true-breeding parentals, all offspring were
brown. What does this mean?
A) I can not decide on domiance relationships until I see the ratios of the F2
Exam Questions and CORRECT Answers
For the following two questions, consider the following double-stranded DNA sequence:
5'-ATCATGCCATG-3'
3'-TAGTACGGTAC-5'
1) How many hydrogen bonds are represented in this double helix?
A) 16 B) 9 C) 20 D) 27 E) 8 - CORRECT ANSWER -D
5'-ATCATGCCATG-3'
3'-TAGTACGGTAC-5'
2) How many phosphodiester bonds are represented in this double helix?
A) 9 B) 23 C) 8 D) 20 E) 16 - CORRECT ANSWER -D
aa Bb Cc DD Ee FF
3) How many different gametes can this individual produce?
A) 10 B) 6 C) 12 D) 8 E) 24 - CORRECT ANSWER -D
4) Suppose only one of the gametes is randomly selected. What is the probability that the gamete
with the following combination of alleles is selected?
abCDeF
A) 1/12 B) 1/24 C) 1/8 D) 1/4 E) 1/6 - CORRECT ANSWER -C
5) InDrosophila virilis, nuclei of somatic cells contain 12 chromosomes while nuclei of sperm
cells
contain only 6 chromosomes. What does "n" equal for this species?
A) 12
B) 24
,C) 3
D) 6 or 12, depending on cell type
E) 6 - CORRECT ANSWER -E
6) Which evolutionary process relies on the premises that individuals with the best adaptations
are
most successful at reproducing and leave more offspring than those with less adaptive forms
and that those adaptations have genetic basis?
A) migration
B) natural selection
C) mutation
D) population genetics
E) random genetic drift - CORRECT ANSWER -B
7) Consider a cross between two individuals with the following genotypes at three traits that
assort
independently:
Rr Ss TT x rr Ss Tt
What is the probability that an offspring will be R/r; s/s; T/T?
A) 5/8 B) 1/16 C) 1/4 D) 1/8 E) 3/8 - CORRECT ANSWER -B
8) Consider the cross of the previous question , and assume all capital alleles are dominant. What
is
the probability of having an offspring that shows all the dominant traits?
A) 3/4 B) 3/8 C) 1/4 D) 1/8 E) 3/16 - CORRECT ANSWER -B
9) Mutations at theRb gene lead to dominant cancer that has incomplete penetrance. How is the
penetrance explained?
A) Cancer will develop in Rb+Rb- individuals when cells become homozygoues for the Rballele
, after rare mitotic recombination events.
B) Penetrance is due to the interaction with the environment.
C) Rb-Rb- is lethal
D) Incomplete penetrance is due to interactions with other genes.
E) There is codominance. - CORRECT ANSWER -A
10) Crossingover involves the breakage and reunion of DNA molecules from...
A) non-homologous nonsister chromatids
B) homologous sister chromatids
C) None of the choices are correct
D) non-homologous sister chromatids
E) homologous nonsister chromatid - CORRECT ANSWER -E
11) If you are a male, your X chromosome contains genes derived from...
A) both your paternal grandfather and grandmother
B) your maternal grandfather only
C) both your paternal and maternal grandfathers
D) both your maternal grandfather and grandmother
E) your paternal grandfather only - CORRECT ANSWER -D
12) If genes assort independently, a testcrossed dihybrid characteristically produces progeny
phenotypes in the ratio ...
A) 9:3:3:1 B) 3:1 C) 1:1:1:1 D) 1:1 E) 1:2:1 - CORRECT ANSWER -C
13) Suppose you were investigating a seed color trait determined by a single locus: green versus
brown. When you performed the first cross between true-breeding parentals, all offspring were
brown. What does this mean?
A) I can not decide on domiance relationships until I see the ratios of the F2
