Question 1

Which of the following best describes the central dogma of molecular biology?

Accepted Answer

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

Question 2

During transcription, which enzyme is responsible for synthesizing the mRNA strand?

Accepted Answer

RNA polymerase

Question 3

Which of the following is a key difference between DNA and RNA molecules?

Accepted Answer

DNA contains deoxyribose, while RNA contains ribose.

Question 4

A gene has the following DNA template strand sequence: 3'-TACGGTACG-5'. What is the corresponding mRNA sequence?

Accepted Answer

5'-AUGCCAUGC-3'

Question 5

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

Accepted Answer

It is redundant, meaning multiple codons can code for the same amino acid.

Question 6

Given the mRNA sequence 5'-AUGGCCUAA-3', what is the resulting amino acid sequence?

Accepted Answer

Met-Ala-Stop

Question 7

What is the function of the promoter region in a gene?

Accepted Answer

It is the DNA sequence where RNA polymerase binds to initiate transcription.

Question 8

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

Accepted Answer

It has remained relatively unchanged throughout evolution.

Question 9

During translation, what is the role of tRNA?

Accepted Answer

It brings amino acids to the ribosome and matches them to the mRNA codon via its anticodon.

Question 10

A mutation changes the codon UAU (tyrosine) to UAA. What is the consequence of this mutation?

Accepted Answer

Translation will terminate prematurely due to a stop codon.

Question 11

Which of the following best describes the process of translation elongation?

Accepted Answer

Amino acids are added one by one to the growing polypeptide chain at the ribosome.

Question 12

Which of the following is a consequence of the redundancy of the genetic code?

Accepted Answer

A single amino acid can be specified by multiple codons.

Question 13

Which of the following is NOT a difference between DNA and RNA?

Accepted Answer

DNA contains ribose, RNA contains deoxyribose.

Question 14

Which of the following best describes a prion?

Accepted Answer

A misfolded protein that can induce other proteins to misfold, causing disease.

Question 15

In bacteria, why can translation begin before transcription is finished?

Accepted Answer

Transcription and translation both occur in the cytoplasm, allowing simultaneous processes.

Question 16

Which of the following sequences is the correct order of events in gene expression?

Accepted Answer

Transcription → Translation → Protein folding

Question 17

A scientist observes that a certain amino acid is coded by four different codons. This is an example of which property of the genetic code?

Accepted Answer

Redundancy

Question 18

Which of the following best explains why plaques are found in the brains of patients with prion diseases?

Accepted Answer

Plaques are accumulations of misfolded prion proteins, used for diagnosis.

Question 19

Which of the following is the correct anticodon sequence for a tRNA carrying the amino acid methionine (start codon AUG)?

Accepted Answer

UAC

Question 20

A mutation in the promoter region of a gene would most likely result in which of the following?

Accepted Answer

Reduced or abolished transcription of the gene.

Gene Expression: Transcription and Translation in Microbiology

Study Guide - Practice Questions