Question 1

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

Accepted Answer

DNA is transcribed into mRNA, which is then translated into protein.

Question 2

Given the DNA template strand 3'-TACGGTAGC-5', what is the sequence of the resulting mRNA molecule?

Accepted Answer

5'-AUGCCAUCG-3'

Question 3

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

Accepted Answer

The genetic code is redundant, meaning multiple codons can specify the same amino acid.

Question 4

A mutation changes the DNA sequence from 3'-TACGTTGGA-5' to 3'-TACGTCGGA-5'. What type of mutation is this, and what is its likely effect?

Accepted Answer

Missense mutation; a different amino acid is incorporated.

Question 5

Which modification is NOT part of eukaryotic RNA processing?

Accepted Answer

Removal of introns.

Question 6

If the mRNA sequence is 5'-AUGGCCUAA-3', what is the resulting amino acid sequence?

Accepted Answer

Met-Ala-Stop

Question 7

Which of the following best explains why a nonsense mutation early in a gene is more severe than one near the end?

Accepted Answer

It causes the protein to be completely non-functional due to premature termination.

Question 8

What is the function of the signal peptide during translation?

Accepted Answer

It guides the ribosome to the endoplasmic reticulum for protein targeting.

Question 9

Which of the following is a real-world example of the universality of the genetic code?

Accepted Answer

A gene from a firefly inserted into a tobacco plant causes the plant to glow.

Question 10

Which enzyme is responsible for catalyzing transcription?

Accepted Answer

RNA polymerase

Question 11

A frameshift mutation occurs when:

Accepted Answer

A nucleotide is inserted or deleted, altering the reading frame.

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 different combinations of exons.

Question 13

Which of the following codons is the start codon for translation?

Accepted Answer

AUG

Question 14

What is the role of tRNA during translation?

Accepted Answer

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

Question 15

Which of the following is a post-translational modification?

Accepted Answer

Addition of a methyl group to a protein.

Question 16

A protein destined for secretion from the cell is most likely synthesized by:

Accepted Answer

Bound ribosomes attached to the endoplasmic reticulum.

Question 17

Which of the following best describes a missense mutation?

Accepted Answer

A mutation that changes one amino acid to another.

Question 18

Given the mRNA sequence 5'-AUGGUAUGA-3', what is the resulting amino acid sequence?

Accepted Answer

Met-Val-Stop

Question 19

Which of the following is a function of the 5' cap added during eukaryotic RNA processing?

Accepted Answer

It facilitates export of mRNA from the nucleus.

Question 20

Which of the following best describes the effect of a frameshift mutation that deletes two nucleotides from a gene?

Accepted Answer

It alters the reading frame, potentially changing every amino acid downstream.

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

Study Guide - Practice Questions