CHEM 210 Biochemistry Module 6 Exam
(2025–2026) | Portage Learning | Verified
Questions and Answers with Detailed Rationales
| Comprehensive Module 6 Study Guide | Latest
Update | Graded A+
THIS EXAM INCLUDES:
✔ Complete CHEM 210 Module 6 review
✔ Verified multiple-choice and conceptual questions
✔ Correct answers with detailed explanations and rationales
✔ High-yield concepts frequently tested on Portage Learning
assessments
✔ Updated 2025–2026 format
✔ Printable PDF format
✔ Ideal for quizzes, module exams, and cumulative final review
,Nucleic Acids Test Bank with Rationales
Question 1
In RNA, guanine always pairs with ______
A. thymine
B. guanine
C. cytosine
D. uracil
E. both A and B
Answer: C. cytosine
Rationale: In RNA, base pairing follows the same complementary rules as DNA with one
exception. Guanine (G) pairs with cytosine (C) through three hydrogen bonds. This is
true for both DNA and RNA. Thymine is replaced by uracil in RNA, but guanine still pairs
with cytosine.
Question 2
DNA is built from which of the following?
A. nucleosides
B. genes
C. purines
D. nucleotides
E. codons
, Answer: D. nucleotides
Rationale: Nucleotides are the monomeric building blocks of nucleic acids. Each
nucleotide consists of a nitrogenous base, a pentose sugar, and a phosphate group.
Nucleosides lack the phosphate group, genes and codons are functional units, and
purines are just one type of nitrogenous base.
Question 3
The Z-form helix of DNA is stabilized mainly by ______
A. ionic bonds
B. covalent bonds
C. hydrogen bonds
D. ion-dipole bonds
E. hydrogen covalent bonds
Answer: C. hydrogen bonds
Rationale: All forms of DNA helices (A, B, and Z forms) are primarily stabilized by
hydrogen bonds between complementary base pairs. While covalent bonds hold the
sugar-phosphate backbone together, hydrogen bonds between adenine-thymine (2
bonds) and guanine-cytosine (3 bonds) maintain the helical structure.
Question 4
Which of the following pentose sugars is a constituent of mRNA?
(2025–2026) | Portage Learning | Verified
Questions and Answers with Detailed Rationales
| Comprehensive Module 6 Study Guide | Latest
Update | Graded A+
THIS EXAM INCLUDES:
✔ Complete CHEM 210 Module 6 review
✔ Verified multiple-choice and conceptual questions
✔ Correct answers with detailed explanations and rationales
✔ High-yield concepts frequently tested on Portage Learning
assessments
✔ Updated 2025–2026 format
✔ Printable PDF format
✔ Ideal for quizzes, module exams, and cumulative final review
,Nucleic Acids Test Bank with Rationales
Question 1
In RNA, guanine always pairs with ______
A. thymine
B. guanine
C. cytosine
D. uracil
E. both A and B
Answer: C. cytosine
Rationale: In RNA, base pairing follows the same complementary rules as DNA with one
exception. Guanine (G) pairs with cytosine (C) through three hydrogen bonds. This is
true for both DNA and RNA. Thymine is replaced by uracil in RNA, but guanine still pairs
with cytosine.
Question 2
DNA is built from which of the following?
A. nucleosides
B. genes
C. purines
D. nucleotides
E. codons
, Answer: D. nucleotides
Rationale: Nucleotides are the monomeric building blocks of nucleic acids. Each
nucleotide consists of a nitrogenous base, a pentose sugar, and a phosphate group.
Nucleosides lack the phosphate group, genes and codons are functional units, and
purines are just one type of nitrogenous base.
Question 3
The Z-form helix of DNA is stabilized mainly by ______
A. ionic bonds
B. covalent bonds
C. hydrogen bonds
D. ion-dipole bonds
E. hydrogen covalent bonds
Answer: C. hydrogen bonds
Rationale: All forms of DNA helices (A, B, and Z forms) are primarily stabilized by
hydrogen bonds between complementary base pairs. While covalent bonds hold the
sugar-phosphate backbone together, hydrogen bonds between adenine-thymine (2
bonds) and guanine-cytosine (3 bonds) maintain the helical structure.
Question 4
Which of the following pentose sugars is a constituent of mRNA?
