Genetics Midterm II UPDATED ACTUAL
Exam Questions and CORRECT Answers
1. Which enzyme untwists the parent strands of DNA during replication?
a. DNA helicase
b. DNA polymerases
c. DNA exonuclease
d. DNA ligase
e. DNA primase - CORRECT ANSWER - DNA helices
2. Tetrad analysis is a technique for
a. Determining base sequences in DNA
b. Mapping genes in organisms retaining the four meiotic products in one structure
c. Measuring the number of chromatids at meiosis
d. Separating Neurospora mycelia - CORRECT ANSWER - Mapping genes in organisms
retaining the four meiotic products in one structure
3. The enzymes most directly concerned with catalyzing DNA synthesis is
a. DNA helicase
b. DNA exonuclease
c. DNA polymerase
d. DNA ligase
e. DNA primase - CORRECT ANSWER - DNA polymerase
4. What did Lederberg and Tatum's 1946-experiment show?
A. That viruses are required for genetic exchange between bacterial cells
B. That bacterial cells can be made to uptake bits of DNA from the environment
C. That genetic recombination in bacteria occurs at a very high rate
,D. That sexual recombination can occur between bacterial cells
E. That genetic exchange between bacterial cells is a bidirectional process - CORRECT
ANSWER - That sexual recombination can occur between bacterial cells
5. DNA and RNA are polymers of
A. pentose sugars connected by phosphodiester bonds
B. nuclease
C. nucleosides
D. ribonucleotides
E. nucleotides - CORRECT ANSWER - nucleotides
6. During transcription, the synthesis of the mRNA strand proceeds in which direction?
A. 5' to 3' only
B. 3' to 5' only
C. Both 5' to 3' and 3' to 5'
D. Either 5' to 3' or 3' to 5'
E. First 5' to 3', and then 3' to 5' - CORRECT ANSWER - 5' to 3' only
7. Nucleosomes typically consist of which of the following?
I. DNA; II. Histones; III. Microtubules
a. I only
b. II only
c. I and III Only
d. II and III Only
e. I and II Only - CORRECT ANSWER - I and II Only
8. A StrR mutant:
A) can grow in the presence of streptomycin.
, B) can make its own streptomycin.
C) cannot grow in the presence of streptomycin.
D) cannot grow without streptomycin.
E) cannot make its own streptomycin - CORRECT ANSWER - can grow in the presence
of streptomycin.
9. Phage that can grow using either a lytic or lysogenic pathway are called
a. virulent
b. temperate
c. intemperate
d. transductant - CORRECT ANSWER - temperate
10. Analysis of bases of a nucleic acid sample yielded the following result: A, 32%; G, 17%; C,
18%; U, 33%. The sample is most likely
a. Single - stranded RNA
b. Double - stranded RNA
c. Single - stranded DNA
d. Double - stranded DNA - CORRECT ANSWER - Double - stranded RNA
11. An example of a heritable disease that results from a biochemical defect in a nonenzymatic
protein is,
a. Cystic fibrosis
b. Lesch-Nyhan syndrome
c. Alkaptonuria
d. Tay-Sachs disease
e. Phenylketonuria - CORRECT ANSWER - Cystic fibrosis
12. The majority of naturally occurring DNA form in humans is
a. Z form.
Exam Questions and CORRECT Answers
1. Which enzyme untwists the parent strands of DNA during replication?
a. DNA helicase
b. DNA polymerases
c. DNA exonuclease
d. DNA ligase
e. DNA primase - CORRECT ANSWER - DNA helices
2. Tetrad analysis is a technique for
a. Determining base sequences in DNA
b. Mapping genes in organisms retaining the four meiotic products in one structure
c. Measuring the number of chromatids at meiosis
d. Separating Neurospora mycelia - CORRECT ANSWER - Mapping genes in organisms
retaining the four meiotic products in one structure
3. The enzymes most directly concerned with catalyzing DNA synthesis is
a. DNA helicase
b. DNA exonuclease
c. DNA polymerase
d. DNA ligase
e. DNA primase - CORRECT ANSWER - DNA polymerase
4. What did Lederberg and Tatum's 1946-experiment show?
A. That viruses are required for genetic exchange between bacterial cells
B. That bacterial cells can be made to uptake bits of DNA from the environment
C. That genetic recombination in bacteria occurs at a very high rate
,D. That sexual recombination can occur between bacterial cells
E. That genetic exchange between bacterial cells is a bidirectional process - CORRECT
ANSWER - That sexual recombination can occur between bacterial cells
5. DNA and RNA are polymers of
A. pentose sugars connected by phosphodiester bonds
B. nuclease
C. nucleosides
D. ribonucleotides
E. nucleotides - CORRECT ANSWER - nucleotides
6. During transcription, the synthesis of the mRNA strand proceeds in which direction?
A. 5' to 3' only
B. 3' to 5' only
C. Both 5' to 3' and 3' to 5'
D. Either 5' to 3' or 3' to 5'
E. First 5' to 3', and then 3' to 5' - CORRECT ANSWER - 5' to 3' only
7. Nucleosomes typically consist of which of the following?
I. DNA; II. Histones; III. Microtubules
a. I only
b. II only
c. I and III Only
d. II and III Only
e. I and II Only - CORRECT ANSWER - I and II Only
8. A StrR mutant:
A) can grow in the presence of streptomycin.
, B) can make its own streptomycin.
C) cannot grow in the presence of streptomycin.
D) cannot grow without streptomycin.
E) cannot make its own streptomycin - CORRECT ANSWER - can grow in the presence
of streptomycin.
9. Phage that can grow using either a lytic or lysogenic pathway are called
a. virulent
b. temperate
c. intemperate
d. transductant - CORRECT ANSWER - temperate
10. Analysis of bases of a nucleic acid sample yielded the following result: A, 32%; G, 17%; C,
18%; U, 33%. The sample is most likely
a. Single - stranded RNA
b. Double - stranded RNA
c. Single - stranded DNA
d. Double - stranded DNA - CORRECT ANSWER - Double - stranded RNA
11. An example of a heritable disease that results from a biochemical defect in a nonenzymatic
protein is,
a. Cystic fibrosis
b. Lesch-Nyhan syndrome
c. Alkaptonuria
d. Tay-Sachs disease
e. Phenylketonuria - CORRECT ANSWER - Cystic fibrosis
12. The majority of naturally occurring DNA form in humans is
a. Z form.
