BIOS 255 Week 3 Quiz Exam 2 (Latest
Update ) Anatomy and
Physiology IV with Lab | Questions &
Answers | 100% Correct | Grade A -
Chamberlain
1. What type of bond holds the two strands of DNA together?
A. Covalent bond
B. Hydrogen bond
C. Ionic bond
D. Peptide bond
Correct Answer: B
Rationale: Hydrogen bonds form between complementary
nitrogenous bases, stabilizing the DNA double helix.
2. Which base pairs with adenine in DNA?
A. Cytosine
B. Guanine
C. Thymine
D. Uracil
Correct Answer: C
Rationale: In DNA, adenine forms two hydrogen bonds with
thymine.
,3. Which base is found in RNA but not DNA?
A. Thymine
B. Uracil
C. Adenine
D. Cytosine
Correct Answer: B
Rationale: Uracil replaces thymine in RNA.
4. What is the main function of mRNA?
A. Stores genetic information
B. Synthesizes proteins
C. Carries genetic code from DNA to ribosomes
D. Modifies proteins
Correct Answer: C
Rationale: mRNA serves as a template for protein synthesis.
5. Which enzyme unwinds DNA during replication?
A. DNA polymerase
B. Helicase
C. Ligase
D. Primase
Correct Answer: B
Rationale: Helicase separates the two DNA strands by breaking
hydrogen bonds.
,6. Which enzyme synthesizes RNA primers during replication?
A. DNA polymerase
B. Primase
C. Ligase
D. Helicase
Correct Answer: B
Rationale: Primase creates RNA primers to initiate DNA synthesis.
7. Which enzyme joins Okazaki fragments on the lagging strand?
A. DNA polymerase
B. Ligase
C. Helicase
D. Primase
Correct Answer: B
Rationale: DNA ligase seals nicks between Okazaki fragments.
8. Which strand is synthesized continuously during DNA
replication?
A. Lagging strand
B. Leading strand
C. Template strand
D. RNA strand
Correct Answer: B
Rationale: The leading strand is synthesized continuously in the 5’
to 3’ direction.
, 9. Which strand is synthesized in fragments during replication?
A. Lagging strand
B. Leading strand
C. Template strand
D. Coding strand
Correct Answer: A
Rationale: The lagging strand is synthesized in Okazaki fragments.
10. Which enzyme adds nucleotides to a growing DNA strand?
A. Helicase
B. DNA polymerase
C. Ligase
D. Primase
Correct Answer: B
Rationale: DNA polymerase catalyzes the addition of nucleotides
complementary to the template.
11. Which molecule is the energy source for DNA polymerase?
A. ATP
B. dNTPs
C. GTP
D. NADPH
Correct Answer: B
Rationale: Deoxyribonucleoside triphosphates (dNTPs) provide
energy for DNA synthesis.
Update ) Anatomy and
Physiology IV with Lab | Questions &
Answers | 100% Correct | Grade A -
Chamberlain
1. What type of bond holds the two strands of DNA together?
A. Covalent bond
B. Hydrogen bond
C. Ionic bond
D. Peptide bond
Correct Answer: B
Rationale: Hydrogen bonds form between complementary
nitrogenous bases, stabilizing the DNA double helix.
2. Which base pairs with adenine in DNA?
A. Cytosine
B. Guanine
C. Thymine
D. Uracil
Correct Answer: C
Rationale: In DNA, adenine forms two hydrogen bonds with
thymine.
,3. Which base is found in RNA but not DNA?
A. Thymine
B. Uracil
C. Adenine
D. Cytosine
Correct Answer: B
Rationale: Uracil replaces thymine in RNA.
4. What is the main function of mRNA?
A. Stores genetic information
B. Synthesizes proteins
C. Carries genetic code from DNA to ribosomes
D. Modifies proteins
Correct Answer: C
Rationale: mRNA serves as a template for protein synthesis.
5. Which enzyme unwinds DNA during replication?
A. DNA polymerase
B. Helicase
C. Ligase
D. Primase
Correct Answer: B
Rationale: Helicase separates the two DNA strands by breaking
hydrogen bonds.
,6. Which enzyme synthesizes RNA primers during replication?
A. DNA polymerase
B. Primase
C. Ligase
D. Helicase
Correct Answer: B
Rationale: Primase creates RNA primers to initiate DNA synthesis.
7. Which enzyme joins Okazaki fragments on the lagging strand?
A. DNA polymerase
B. Ligase
C. Helicase
D. Primase
Correct Answer: B
Rationale: DNA ligase seals nicks between Okazaki fragments.
8. Which strand is synthesized continuously during DNA
replication?
A. Lagging strand
B. Leading strand
C. Template strand
D. RNA strand
Correct Answer: B
Rationale: The leading strand is synthesized continuously in the 5’
to 3’ direction.
, 9. Which strand is synthesized in fragments during replication?
A. Lagging strand
B. Leading strand
C. Template strand
D. Coding strand
Correct Answer: A
Rationale: The lagging strand is synthesized in Okazaki fragments.
10. Which enzyme adds nucleotides to a growing DNA strand?
A. Helicase
B. DNA polymerase
C. Ligase
D. Primase
Correct Answer: B
Rationale: DNA polymerase catalyzes the addition of nucleotides
complementary to the template.
11. Which molecule is the energy source for DNA polymerase?
A. ATP
B. dNTPs
C. GTP
D. NADPH
Correct Answer: B
Rationale: Deoxyribonucleoside triphosphates (dNTPs) provide
energy for DNA synthesis.
