Question 1

Which of the following best describes the central dogma of molecular biology as proposed by Francis Crick?

Accepted Answer

DNA is transcribed into RNA, which is then translated into protein.

Question 2

In the Beadle and Tatum experiment with Neurospora crassa, which class of mutants could grow only when arginine was added to the medium?

Accepted Answer

Class III mutants

Question 3

Which enzyme is responsible for synthesizing mRNA from a DNA template during transcription?

Accepted Answer

RNA polymerase

Question 4

What is the function of the 5' cap and poly-A tail added to eukaryotic pre-mRNA during RNA processing?

Accepted Answer

They help the mRNA bind to ribosomes and protect it from degradation.

Question 5

A point mutation that changes a codon for one amino acid into a stop codon is called a:

Accepted Answer

Nonsense mutation

Question 6

Which of the following statements about the genetic code is correct?

Accepted Answer

It is redundant, with multiple codons coding for the same amino acid.

Question 7

During translation, what is the role of tRNA?

Accepted Answer

It brings amino acids to the ribosome and matches them to the mRNA codons.

Question 8

What is the consequence of a frameshift mutation caused by a nucleotide insertion or deletion?

Accepted Answer

It alters the reading frame, potentially changing every amino acid downstream.

Question 9

Which of the following best explains why prokaryotic gene expression can occur more rapidly than in eukaryotes?

Accepted Answer

Transcription and translation are coupled in prokaryotes due to the lack of a nuclear envelope.

Question 10

Which of the following is NOT a function of spliceosomes?

Accepted Answer

Adding a 5' cap to mRNA

Question 11

A mutation in the TATA box of a eukaryotic gene would most likely affect which process?

Accepted Answer

Initiation of transcription

Question 12

Which of the following best describes a polyribosome?

Accepted Answer

A group of ribosomes translating a single mRNA simultaneously

Question 13

Which of the following is a property of RNA that allows it to function as an enzyme (ribozyme)?

Accepted Answer

It can form complex three-dimensional shapes.

Question 14

What is the function of aminoacyl-tRNA synthetase in translation?

Accepted Answer

It attaches the correct amino acid to its corresponding tRNA.

Question 15

Which of the following codons signals the start of translation?

Accepted Answer

AUG

Question 16

A scientist discovers a mutation that changes the third base of a codon but does not alter the amino acid sequence of the protein. What type of mutation is this?

Accepted Answer

Silent mutation

Question 17

Which of the following best describes the role of the release factor during translation termination?

Accepted Answer

It binds to the stop codon and releases the polypeptide from the ribosome.

Question 18

Which of the following is a direct result of alternative splicing of pre-mRNA in eukaryotes?

Accepted Answer

Production of different protein isoforms from a single gene

Question 19

Which of the following best explains the medical significance of the difference between prokaryotic and eukaryotic ribosomes?

Accepted Answer

Antibiotics can target prokaryotic ribosomes without affecting eukaryotic ribosomes.

Question 20

Which of the following statements about the CRISPR-Cas9 system is correct?

Accepted Answer

Cas9 is a protein that cuts DNA at specific sites guided by RNA.

Step-by-Step Guidance for Chapter 17: Gene Expression and Protein Synthesis

Study Guide - Practice Questions

Study Guide - Flashcards