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 RNA from a DNA template?

Accepted Answer

RNA polymerase

Question 3

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

Accepted Answer

RNA contains deoxyribose sugar.

Question 4

What is the function of mRNA in gene expression?

Accepted Answer

It serves as a template for protein synthesis by carrying genetic information from DNA to the ribosome.

Question 5

Where does translation occur in eukaryotic cells?

Accepted Answer

On the ribosomes in the cytoplasm

Question 6

How does gene expression differ between prokaryotes and eukaryotes?

Accepted Answer

In prokaryotes, transcription and translation can occur simultaneously in the cytoplasm.

Question 7

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

Accepted Answer

5'-UACGCA-3'

Question 8

What is a codon?

Accepted Answer

A three-nucleotide sequence on mRNA that codes for a specific amino acid.

Question 9

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

Accepted Answer

It is universal, with few exceptions across all organisms.

Question 10

A mutation that changes a codon from UAU (tyrosine) to UAA (stop) is an example of which type of mutation?

Accepted Answer

Nonsense mutation

Question 11

What is the main advantage of the 5’ cap and poly-A tail added to eukaryotic mRNA?

Accepted Answer

They help the mRNA exit the nucleus and protect it from degradation.

Question 12

Which of the following best describes alternative RNA splicing?

Accepted Answer

It allows a single gene to code for multiple proteins by including or excluding certain exons.

Question 13

What is the function of tRNA during translation?

Accepted Answer

It carries amino acids to the ribosome and matches them to the coded mRNA message.

Question 14

Which of the following best describes a frameshift mutation?

Accepted Answer

A mutation that results from the insertion or deletion of nucleotides, altering the reading frame.

Question 15

Which of the following is a function of ribosomes in the process of translation?

Accepted Answer

They catalyze the formation of peptide bonds between amino acids.

Question 16

A scientist introduces a chemical mutagen to a culture of cells. What is the most likely effect of this mutagen?

Accepted Answer

It will increase the rate of mutations in the DNA.

Question 17

Which of the following best explains why mutations are important for evolution?

Accepted Answer

Mutations create genetic variation, which can be acted upon by natural selection.

Question 18

During translation, what is the role of the anticodon?

Accepted Answer

It is a three-nucleotide sequence on tRNA that pairs with the complementary codon on mRNA.

Question 19

Which of the following best describes a missense mutation?

Accepted Answer

A mutation that changes a codon to one that codes for a different amino acid.

Question 20

Which of the following equations correctly represents the flow of genetic information according to the central dogma?

Accepted Answer

$DNA \rightarrow RNA \rightarrow Protein$

Step-by-Step Guidance for Gene Expression: From Gene to Protein

Study Guide - Practice Questions