Question 1

Which of the following correctly describes the structure of a nucleotide?

Accepted Answer

A phosphate group, a pentose sugar, and a nitrogenous base

Question 2

Which of the following is a purine nitrogenous base found in DNA?

Accepted Answer

Adenine

Question 3

What is the difference between a nucleoside and a nucleotide?

Accepted Answer

A nucleotide contains a phosphate group, while a nucleoside does not

Question 4

Which carbon of the deoxyribose sugar in DNA is attached to the phosphate group in a polynucleotide chain?

Accepted Answer

$5'$ carbon

Question 5

Which of the following best describes the antiparallel orientation of DNA?

Accepted Answer

The two strands run in opposite directions: one $5' \rightarrow 3'$ and the other $3' \rightarrow 5'$

Question 6

Which nitrogenous bases are complementary in DNA?

Accepted Answer

Adenine pairs with Thymine, and Guanine pairs with Cytosine

Question 7

Which of the following is true about ATP (adenosine triphosphate)?

Accepted Answer

ATP contains three phosphate groups attached to adenosine

Question 8

During the formation of a phosphodiester linkage in DNA, which carbons of the sugar are involved?

Accepted Answer

$3'$ carbon of one nucleotide and $5'$ carbon of the next nucleotide

Question 9

Which of the following best defines a gene?

Accepted Answer

A segment of DNA that codes for a functional product, usually a protein

Question 10

Which process describes the conversion of genetic information from DNA into a functional product?

Accepted Answer

Gene expression

Question 11

Which of the following statements about RNA is correct?

Accepted Answer

RNA contains uracil instead of thymine

Question 12

A scientist is analyzing a DNA molecule and finds that 30% of its bases are adenine. What percentage of the bases are cytosine?

Accepted Answer

20%

Question 13

Which of the following is a pyrimidine nitrogenous base found in RNA?

Accepted Answer

Uracil

Question 14

Which of the following best describes a polynucleotide?

Accepted Answer

A long chain of nucleotides joined by phosphodiester bonds

Question 15

Which of the following is the correct formula for the number of hydrogen bonds between complementary base pairs in DNA?

Accepted Answer

$A-T$ pairs have 2 hydrogen bonds; $G-C$ pairs have 3 hydrogen bonds

Question 16

Which of the following is the correct order of the three components of a nucleotide?

Accepted Answer

Phosphate group, pentose sugar, nitrogenous base

Question 17

Which of the following is true about the orientation of the two strands in a DNA double helix?

Accepted Answer

One strand runs $5' \rightarrow 3'$, and the other runs $3' \rightarrow 5'$

Question 18

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

Accepted Answer

A carboxyl group

Question 19

Which of the following best explains the biological importance of the antiparallel orientation of DNA?

Accepted Answer

It allows complementary base pairing and proper replication of DNA

Question 20

Which of the following statements about the $3'$ and $5'$ ends of a DNA strand is correct?

Accepted Answer

The $5'$ end has a phosphate group attached, and the $3'$ end has a hydroxyl group attached

Nucleic Acids: Structure, Function, and Key Concepts

Study Guide - Practice Questions