Question 1

Which experiment provided the strongest evidence that DNA, and not protein, is the hereditary material, and what was the key rationale for using bacteriophages in this experiment?

Accepted Answer

The Hershey-Chase experiment; bacteriophages were used because their DNA and protein components could be separately labeled and tracked during infection.

Question 2

Which of the following best describes the structural difference between a ribonucleotide and a deoxyribonucleotide?

Accepted Answer

A ribonucleotide has a hydroxyl group ($$-OH) on $$the 2' carbon of its sugar, while a deoxyribonucleotide has a hydrogen ($$-H) at $$the same position.

Question 3

Which of the following statements about DNA replication is correct?

Accepted Answer

DNA polymerase can add nucleotides only to the 3' end of a growing DNA strand.

Question 4

Which of the following best explains why the genetic code is described as 'redundant'?

Accepted Answer

Multiple codons can specify the same amino acid.

Question 5

A mutation changes the DNA sequence from $$5'-ATG-3' to$$ $$5'-ACG-3'. $$What is the most likely effect on the resulting protein?

Accepted Answer

A single amino acid will be changed, which may or may not affect protein function.

Question 6

Which of the following best describes the role of tRNA during translation?

Accepted Answer

tRNA brings specific amino acids to the ribosome by matching its anticodon to the codon on mRNA.

Question 7

Which of the following is a key difference between prokaryotic and eukaryotic gene expression?

Accepted Answer

In eukaryotes, transcription and translation are separated by the nuclear envelope.

Question 8

Which of the following best defines a frameshift mutation?

Accepted Answer

A mutation that inserts or deletes nucleotides, altering the reading frame of the gene.

Question 9

During eukaryotic mRNA processing, which of the following events occurs?

Accepted Answer

A 5' cap and a poly-A tail are added to the mRNA.

Question 10

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

Accepted Answer

The sugar-phosphate backbone is on the outside, and the nitrogenous bases are on the inside of the double helix.

Question 11

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 should be guanine?

Accepted Answer

$$20\%$$

Question 12

Which of the following best describes the function of DNA ligase during DNA replication?

Accepted Answer

It joins Okazaki fragments together on the lagging strand.

Question 13

Which of the following is true regarding the directionality of nucleic acids?

Accepted Answer

The 5' end of a nucleic acid has a free phosphate group, and the 3' end has a free hydroxyl group.

Question 14

Which of the following best explains why a frameshift mutation is generally more severe than a substitution mutation?

Accepted Answer

Frameshift mutations change the reading frame, potentially altering every amino acid downstream of the mutation.

Question 15

Which of the following is a correct sequence of events during transcription in a eukaryotic cell?

Accepted Answer

Initiation at the promoter, elongation of the RNA strand, termination at the terminator sequence.

Question 16

A DNA template strand has the sequence $$3'-TACGGTACG-5'. $$What is the corresponding mRNA sequence produced during transcription?

Accepted Answer

$$5'-AUGCCAUGC-3'$$

Question 17

Which of the following is a real-world example of a mutagen?

Accepted Answer

Ultraviolet (UV) radiation from sunlight causing thymine dimers in DNA.

Question 18

Which of the following best describes the significance of the 'universal' nature of the genetic code?

Accepted Answer

It allows genes from one organism to be expressed in another, supporting the concept of common ancestry.

Question 19

Which of the following is true regarding the roles of Watson, Crick, and Franklin in the discovery of DNA structure?

Accepted Answer

Watson and Crick used Franklin's X-ray diffraction data to build their double helix model.

Chapter 10: Molecular Biology of the Gene – Study Guide

Study Guide - Practice Questions

Study Guide - Flashcards