Question 1

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

Accepted Answer

The unidirectional flow of genetic information from DNA to RNA to protein.

Question 2

During transcription, which enzyme is responsible for synthesizing RNA from a DNA template?

Accepted Answer

RNA polymerase

Question 3

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

Accepted Answer

5'-AUGCCAUGC-3'

Question 4

Which of the following modifications occur to eukaryotic pre-mRNA before it becomes mature mRNA?

Accepted Answer

Addition of a 5' cap and a poly-A tail

Question 5

What is the function of the spliceosome during RNA processing?

Accepted Answer

It removes introns from pre-mRNA and joins exons together.

Question 6

Which type of RNA contains codons that specify amino acids?

Accepted Answer

mRNA

Question 7

A mutation changes the DNA sequence from AGC to AGG. If both codons code for different amino acids, what type of mutation is this?

Accepted Answer

Missense mutation

Question 8

Which of the following statements about translation is correct?

Accepted Answer

Translation occurs in the cytoplasm and synthesizes proteins from mRNA templates.

Question 9

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

Accepted Answer

Met-Ala-Stop

Question 10

Which of the following best explains why a frameshift mutation is often more severe than a point mutation?

Accepted Answer

A frameshift mutation alters the reading frame, changing every amino acid downstream.

Question 11

Which of the following is a post-translational modification that can regulate protein activity?

Accepted Answer

Phosphorylation

Question 12

What is the role of tRNA during translation?

Accepted Answer

It brings specific amino acids to the ribosome based on codon-anticodon pairing.

Question 13

Which of the following is true regarding the redundancy of the genetic code?

Accepted Answer

There are more codons than amino acids, so some amino acids are specified by more than one codon.

Question 14

A mutation in the DNA sequence results in a premature stop codon. What is this type of mutation called?

Accepted Answer

Nonsense mutation

Question 15

Which of the following events occurs during the initiation phase of translation?

Accepted Answer

The small ribosomal subunit binds to the mRNA and the initiator tRNA.

Question 16

Which of the following is NOT a property shared by both RNA polymerase and DNA polymerase?

Accepted Answer

Can initiate strand synthesis without a primer.

Question 17

If a DNA coding strand has the sequence 5'-ATGCGT-3', what is the sequence of the mRNA produced from the template strand?

Accepted Answer

5'-AUGCGU-3'

Question 18

Which of the following best describes the function of the poly-A tail added to eukaryotic mRNA?

Accepted Answer

It protects the mRNA from degradation and assists in export from the nucleus.

Question 19

Which of the following is the correct order of events in gene expression according to the central dogma?

Accepted Answer

DNA → RNA → Protein

Question 20

A section of DNA has the sequence 5'-AGT-3' on the template strand. What is the corresponding mRNA codon?

Accepted Answer

5'-ACU-3'

Gene Expression: From DNA to Protein (Central Dogma, Transcription, Translation, and Mutations)

Study Guide - Practice Questions