Q: Which of the following best explains the antiparallel nature of DNA strands?

One strand runs in the $5' \to 3'$ direction, while the other runs in the $3' \to 5'$ direction

Q: Given the DNA template strand $3'\text{–}GCATAGTCCG\text{–}5'$, what is the sequence of the complementary DNA strand?

$5'\text{–}CGTATCAGGC\text{–}3'$

Question 1

Which of the following best describes the three basic components of a nucleotide?

Accepted Answer

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

Question 2

During the formation of a nucleic acid polymer, which type of bond connects the 3' carbon of one nucleotide's sugar to the 5' phosphate of the next nucleotide?

Accepted Answer

A phosphodiester bond

Question 3

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

Accepted Answer

DNA contains deoxyribose sugar, while RNA contains ribose sugar

Question 4

Which of the following is a pyrimidine found in RNA but not in DNA?

Accepted Answer

Uracil

Question 5

A scientist is analyzing a DNA molecule and finds that 30% of the bases are adenine. According to Chargaff's rules, what percentage of the bases are cytosine?

Accepted Answer

$20\%$

Question 6

Which of the following best explains the antiparallel nature of DNA strands?

Accepted Answer

One strand runs in the $5' 	o 3'$ direction, while the other runs in the $3' 	o 5'$ direction

Question 7

Which of the following base-pairing rules is correct for DNA?

Accepted Answer

$A$ pairs with $T$, and $G$ pairs with $C$

Question 8

Given the DNA template strand $3'	ext{–}GCATAGTCCG	ext{–}5'$, what is the sequence of the complementary DNA strand?

Accepted Answer

$5'	ext{–}CGTATCAGGC	ext{–}3'$

Question 9

Which of the following best describes the function of RNA in living organisms?

Accepted Answer

RNA acts as a messenger carrying instructions from DNA for controlling the synthesis of proteins

Question 10

A mutation changes a cytosine in DNA to a thymine. Which type of mutation is this, and what is a possible consequence?

Accepted Answer

A point mutation; it may result in a change in the amino acid sequence of a protein

Question 11

Which of the following statements about the double helix structure of DNA is correct?

Accepted Answer

The two strands are held together by hydrogen bonds between complementary bases

Question 12

Which of the following is a difference between ribose and deoxyribose sugars?

Accepted Answer

Ribose has a hydroxyl group ($-OH$) on the 2' carbon, while deoxyribose has a hydrogen ($-H$) at the same position

Question 13

Which of the following best describes a real-world application of nucleic acid base-pairing?

Accepted Answer

PCR (Polymerase Chain Reaction) uses base-pairing to amplify specific DNA sequences for forensic analysis

Question 14

Which of the following is a purine found in both DNA and RNA?

Accepted Answer

Adenine

Question 15

A patient is diagnosed with a genetic disorder caused by a single nucleotide substitution in a gene. Which molecular process is most directly affected by this mutation?

Accepted Answer

The sequence of amino acids in the resulting protein

Question 16

Which of the following best explains why DNA is a more stable molecule than RNA?

Accepted Answer

DNA lacks a hydroxyl group at the 2' carbon, making it less susceptible to hydrolysis

Question 17

Which of the following best describes the directionality of nucleic acid synthesis?

Accepted Answer

Nucleic acids are synthesized in the $5' 	o 3'$ direction

Question 18

Which of the following is a correct statement about the role of hydrogen bonds in nucleic acids?

Accepted Answer

Hydrogen bonds stabilize the double helix by connecting complementary bases

Question 19

Which of the following best describes the process by which genetic information is transferred from DNA to RNA?

Accepted Answer

Transcription

Question 20

A researcher is designing an experiment to synthesize a new strand of DNA. Which enzyme is required to catalyze the formation of phosphodiester bonds between nucleotides?

Accepted Answer

DNA polymerase

Nucleic Acids: Structure, Function, and Properties

Study Guide - Practice Questions

Study Guide - Flashcards