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

What was the significance of Archibald Garrod's study of alkaptonuria?

Accepted Answer

He provided evidence that genes dictate phenotypes through enzymes that catalyze specific chemical reactions.

Question 3

Beadle and Tatum’s experiments with Neurospora mutants led to which revision of the gene-protein relationship?

Accepted Answer

One gene-one polypeptide hypothesis

Question 4

Which process occurs in the nucleus of eukaryotic cells but not in prokaryotic cells?

Accepted Answer

RNA processing

Question 5

What is the function of the 5' cap and poly-A tail added to eukaryotic mRNA?

Accepted Answer

They facilitate export of mRNA, protect it from degradation, and help ribosome binding.

Question 6

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

Accepted Answer

Nonsense mutation

Question 7

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

Accepted Answer

It is redundant, with multiple codons specifying the same amino acid.

Question 8

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 9

Which enzyme catalyzes the formation of RNA from a DNA template during transcription?

Accepted Answer

RNA polymerase

Question 10

What is the consequence of a frameshift mutation?

Accepted Answer

It may alter the reading frame, changing every amino acid downstream of the mutation.

Question 11

Which of the following best explains why the genetic code is described as 'nearly universal'?

Accepted Answer

All organisms use the same codons for the same amino acids, with very few exceptions.

Question 12

Which of the following is true about alternative RNA splicing?

Accepted Answer

It allows a single gene to code for multiple polypeptides.

Question 13

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

Accepted Answer

It is the site where RNA polymerase binds to initiate transcription.

Question 14

Which of the following best describes a polyribosome?

Accepted Answer

Multiple ribosomes simultaneously translating a single mRNA molecule.

Question 15

Which of the following is a property of ribozymes?

Accepted Answer

They are RNA molecules with catalytic activity.

Question 16

A scientist introduces a mutation that changes the third base of a codon but the same amino acid is incorporated. What is this mutation called?

Accepted Answer

Silent mutation

Question 17

Which of the following is a function of the signal-recognition particle (SRP) during translation?

Accepted Answer

It directs ribosomes synthesizing proteins to the endoplasmic reticulum.

Question 18

Which of the following is true about the difference between prokaryotic and eukaryotic gene expression?

Accepted Answer

In eukaryotes, RNA processing occurs before translation.

Question 19

Which of the following best defines a gene according to modern molecular biology?

Accepted Answer

A region of DNA that can be expressed to produce a final functional product, either a polypeptide or an RNA molecule.

Question 20

Which of the following is a likely consequence of a mutation in the TATA box of a eukaryotic promoter?

Accepted Answer

RNA polymerase may not bind efficiently, reducing or preventing transcription initiation.

Gene Expression: From Gene to Protein (Chapter 17 Study Notes)

Study Guide - Practice Questions