Question 1

Which of the following best describes the main difference between DNA and mRNA?

Accepted Answer

DNA contains deoxyribose sugar, while mRNA contains ribose sugar.

Question 2

A gene is defined as:

Accepted Answer

A region of DNA that carries instructions for making specific proteins.

Question 3

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

Accepted Answer

RNA polymerase

Question 4

Given the DNA template strand 3'–TACGGTAGCATT–5', what is the corresponding mRNA sequence?

Accepted Answer

$$5'–AUGCCAUCGUAA–3'$$

Question 5

Which of the following statements about alternative splicing is correct?

Accepted Answer

It allows a single gene to code for multiple proteins.

Question 6

Which organelle is responsible for the process of translation?

Accepted Answer

Ribosome

Question 7

What is a codon?

Accepted Answer

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

Question 8

Using the genetic code table, what amino acids are encoded by the mRNA sequence 5'–AUGCCAUCG–3'?

Accepted Answer

Met–Pro–Ile

Question 9

Which of the following best explains why neurons and muscle cells produce different proteins despite having the same DNA?

Accepted Answer

They use differential gene expression to selectively express only the genes they need.

Question 10

What is the role of transcription factors in gene expression?

Accepted Answer

They bind to DNA and regulate the rate of transcription.

Question 11

A point mutation changes a codon from UAU (tyrosine) to UAA (stop). What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 12

Which of the following is a possible consequence of a frameshift mutation?

Accepted Answer

The reading frame of the mRNA is shifted, potentially resulting in a nonfunctional protein.

Question 13

Which of the following is NOT a function of the promoter region of a gene?

Accepted Answer

It codes for the amino acid sequence of a protein.

Question 14

Which of the following best describes the effect of histone modifications on gene expression?

Accepted Answer

They can alter chromatin structure, making genes more or less accessible for transcription.

Question 15

A mutation in the INS gene leads to a change in the structure of the insulin protein. Which region of the gene is most likely affected?

Accepted Answer

Protein-coding region (exon)

Question 16

Which of the following is a correct sequence of events in gene expression in a eukaryotic cell?

Accepted Answer

Transcription → RNA processing → Translation

Question 17

If a cell detects a mutation that cannot be repaired, what is one possible cellular response?

Accepted Answer

Apoptosis (programmed cell death)

Question 18

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

Accepted Answer

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

Question 19

A mutation deletes three nucleotides from a gene. What is the most likely result?

Accepted Answer

The reading frame is preserved, but one amino acid is missing from the protein.

Question 20

Which of the following is a real-world example of a disease caused by a large-scale chromosomal mutation?

Accepted Answer

5p Deletion Syndrome (Cri-du-chat syndrome)

Transcription, Translation, and Gene Expression: Cell Biology Study Guide

Study Guide - Practice Questions