Question 1

Which statement best describes the 'one gene, one polypeptide hypothesis'?

Accepted Answer

Each gene codes for a single polypeptide, which may be part of a protein.

Question 2

During transcription, which strand of DNA is used as the template for mRNA synthesis?

Accepted Answer

Template strand

Question 3

Where does translation occur in eukaryotic cells?

Accepted Answer

Cytoplasm

Question 4

What is the 'Central Dogma of Molecular Biology'?

Accepted Answer

DNA \rightarrow RNA \rightarrow Protein

Question 5

What is the significance of codons in protein synthesis?

Accepted Answer

They specify which amino acid will be added during translation.

Question 6

What is meant by 'redundancy of the code' in genetic coding?

Accepted Answer

Multiple codons can code for the same amino acid.

Question 7

Using the codon wheel, what amino acid does the codon AUG code for?

Accepted Answer

Methionine

Question 8

What is the function of the three 'stop' codons in mRNA?

Accepted Answer

They signal the end of translation.

Question 9

Why is the promoter region important for gene expression?

Accepted Answer

It is the binding site for RNA polymerase to initiate transcription.

Question 10

How does RNA polymerase differ from DNA polymerase?

Accepted Answer

RNA polymerase synthesizes RNA from DNA templates, while DNA polymerase synthesizes DNA from DNA templates.

Question 11

Why is RNA splicing important for gene expression in eukaryotes?

Accepted Answer

It removes introns and joins exons, allowing for mature mRNA to be translated.

Question 12

What is the role of tRNA during translation?

Accepted Answer

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

Question 13

Why might a polypeptide be targeted to the endoplasmic reticulum (ER)?

Accepted Answer

For further modification and sorting for secretion or membrane insertion.

Question 14

Which type of mutation is most likely to cause a frameshift?

Accepted Answer

Insertion or deletion of a nucleotide

Question 15

What is the main purpose of gene regulation in both prokaryotes and eukaryotes?

Accepted Answer

To control when and how much a gene is expressed, adapting to environmental and developmental needs.

Question 16

What is the function of an operon in bacteria?

Accepted Answer

To regulate multiple genes together under a single promoter.

Question 17

How does repression differ from induction in gene regulation?

Accepted Answer

Repression turns genes off, induction turns genes on.

Question 18

What effect does glucose have on the lac operon in E. coli?

Accepted Answer

It represses the lac operon even if lactose is present, to conserve energy.

Question 19

What is a nucleosome and why is methylation of its components important?

Accepted Answer

A nucleosome is a DNA-protein complex; methylation of histones or DNA can regulate gene expression by altering chromatin structure.

Question 20

What is the purpose of alternative splicing in eukaryotic gene expression?

Accepted Answer

To produce multiple mRNA molecules from a single gene, increasing protein diversity.

Gene Expression: From Gene to Protein & Regulation of Gene Expression

Study Guide - Practice Questions