Question 1

Which of the following best describes the primary structure of a nucleic acid?

Accepted Answer

A sequence of nitrogen-containing bases linked by phosphodiester bonds

Question 2

What is the correct chemical difference between ribonucleotides and deoxyribonucleotides?

Accepted Answer

Ribonucleotides contain ribose, while deoxyribonucleotides contain deoxyribose

Question 3

Which base pairing is stabilized by three hydrogen bonds in DNA?

Accepted Answer

G-C

Question 4

Why is DNA considered a more reliable store of genetic information than RNA?

Accepted Answer

DNA is less reactive and more resistant to chemical degradation

Question 5

Which of the following statements about the directionality of nucleic acids is correct?

Accepted Answer

The sugar-phosphate backbone has an unlinked 5' carbon at one end and an unlinked 3' carbon at the other

Question 6

Which of the following is a function unique to RNA compared to DNA?

Accepted Answer

Catalysis of chemical reactions

Question 7

A scientist discovers a nucleic acid molecule with the following sequence: 5'-AUGCUU-3'. Which type of nucleic acid is this most likely to be?

Accepted Answer

RNA, because it contains uracil

Question 8

Which of the following best explains why only purine-pyrimidine pairs fit inside the DNA double helix?

Accepted Answer

Purine-purine pairs are too large and pyrimidine-pyrimidine pairs are too small; only purine-pyrimidine pairs fit just right

Question 9

Which of the following is the correct sequence of events during DNA replication?

Accepted Answer

Strand separation, hydrogen bonding of deoxyribonucleotides to template, phosphodiester bond formation

Question 10

Which of the following statements about the secondary structure of RNA is correct?

Accepted Answer

RNA forms hairpin structures by hydrogen bonding between complementary bases on the same strand

Question 11

Which of the following is NOT a component of a nucleotide?

Accepted Answer

Amino group

Question 12

Which empirical rule did Chargaff establish regarding DNA base composition?

Accepted Answer

The numbers of adenines and thymines are equal, and the numbers of guanines and cytosines are equal

Question 13

Which of the following best explains why RNA is more reactive than DNA?

Accepted Answer

RNA contains ribose, which has a hydroxyl group at the 2' carbon

Question 14

Which of the following is a correct description of a phosphodiester bond?

Accepted Answer

A bond between the phosphate group on the 5' carbon of one nucleotide and the —OH group on the 3' carbon of another

Question 15

Which of the following is a function of ribozymes?

Accepted Answer

Catalysis of chemical reactions

Question 16

A mutation replaces a cytosine with a thymine in a DNA molecule. Which type of base pairing will be affected?

Accepted Answer

G-C pairing, which has three hydrogen bonds

Question 17

Which of the following best describes the role of ATP in RNA synthesis?

Accepted Answer

ATP provides energy and acts as a substrate for RNA synthesis

Question 18

Which of the following statements about the major and minor grooves in DNA is correct?

Accepted Answer

The major groove is larger and provides more access for protein binding

Question 19

Which of the following is a plausible reason why DNA does not act as a catalyst in cells?

Accepted Answer

DNA is chemically stable and lacks the functional groups necessary for catalysis

Question 20

Which of the following best explains why RNA is considered a possible precursor to the first life-form?

Accepted Answer

RNA can store genetic information and catalyze chemical reactions

Nucleic Acids: Structure, Function, and the Molecular Basis of Genetic Information

Study Guide - Practice Questions