Question 1

Which of the following is NOT a component of a nucleotide as shown in the provided diagram?

Accepted Answer

A carboxylic acid group

Question 2

The structure in the second image is most similar to which of the following?

Accepted Answer

A spiral staircase

Question 3

Which type of chemical bond links the 3' carbon of one nucleotide to the 5' phosphate of the next in a DNA strand?

Accepted Answer

Phosphodiester bond

Question 4

In the DNA double helix, which interaction provides the most structural stability?

Accepted Answer

Dispersion forces (stacking energy) between aromatic bases

Question 5

Which of the following best describes the directionality of a DNA strand?

Accepted Answer

It runs from the 5' phosphate end to the 3' hydroxyl end.

Question 6

Which of the following base pairs is stabilized by three hydrogen bonds?

Accepted Answer

Guanine–Cytosine

Question 7

Which of the following is a correct reverse complement for the DNA sequence 5' TTT CAG GTG CAT 3'?

Accepted Answer

5' ATG CAC CTG AAA 3'

Question 8

Which of the following statements about DNA and RNA is TRUE?

Accepted Answer

DNA contains deoxyribose and thymine, while RNA contains ribose and uracil.

Question 9

Which amino acid is most likely to be found in the DNA-binding region of a protein, as shown in the first image?

Accepted Answer

Lysine

Question 10

A mutation causes cytosine to be deaminated to uracil in DNA. What is the consequence during DNA replication if this mutation is not repaired?

Accepted Answer

A G–C base pair is replaced by an A–T base pair in one of the daughter DNA molecules.

Question 11

Which of the following is NOT a function of nucleotides or nucleic acids?

Accepted Answer

Forming the primary structure of cell membranes

Question 12

Which of the following best explains why histone proteins are rich in lysine and arginine?

Accepted Answer

They are positively charged and interact with the negatively charged DNA backbone.

Question 13

Which of the following is a correct statement about Chargaff’s rules?

Accepted Answer

The amount of adenine equals the amount of thymine in double-stranded DNA.

Question 14

Which of the following best describes the process of semiconservative replication?

Accepted Answer

Each new DNA double helix contains one old strand and one new strand.

Question 15

Which of the following molecules is NOT a nucleotide-containing cofactor?

Accepted Answer

TPP (thiamine pyrophosphate)

Question 16

Which of the following best describes the major groove of DNA?

Accepted Answer

It is a region where proteins can recognize specific base sequences.

Question 17

Which of the following is a correct description of the difference between a nucleoside and a nucleotide?

Accepted Answer

A nucleoside lacks a phosphate group, while a nucleotide contains one or more phosphate groups.

Question 18

Which of the following best explains why the DNA double helix is antiparallel?

Accepted Answer

The two strands run in opposite 5' to 3' directions.

Question 19

Which of the following is a real-world application of DNA complementarity?

Accepted Answer

Accurate replication of genetic information during cell division

lec 12 Nucleic Acid Structure: DNA, RNA, and Their Biological Roles

Study Guide - Practice Questions