$$\text{DNA} \rightarrow \text{RNA} \rightarrow \text{Proteins}$$

Question 1

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

Accepted Answer

$$	ext{DNA} ightarrow 	ext{RNA} ightarrow 	ext{Proteins}$$

Question 2

Beadle and Tatum’s experiments with Neurospora crassa led to which hypothesis about gene function?

Accepted Answer

One-gene, one-enzyme hypothesis

Question 3

What is the role of messenger RNA (mRNA) in gene expression?

Accepted Answer

It carries information from DNA to the site of protein synthesis.

Question 4

Which enzyme is responsible for synthesizing RNA from a DNA template during transcription?

Accepted Answer

RNA polymerase

Question 5

A mutation changes a codon from $$	ext{UAC} ($$tyrosine) to $$	ext{UAA} ($$stop codon). What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 6

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

Accepted Answer

It is overlapping, with each nucleotide being part of multiple codons.

Question 7

If a DNA sequence is $$	ext{TACGGA}$$, what is the corresponding mRNA sequence produced during transcription?

Accepted Answer

$$	ext{AUGCCU}$$

Question 8

Which type of mutation is most likely to result in a completely nonfunctional protein?

Accepted Answer

Frameshift mutation

Question 9

A segment of a chromosome breaks off, flips around, and rejoins. This is an example of which chromosomal mutation?

Accepted Answer

Inversion

Question 10

Which of the following best explains why different alleles of the same gene can produce different phenotypes?

Accepted Answer

They have different DNA sequences, leading to different amino acid sequences in proteins.

Question 11

Which of the following is a real-life example of a beneficial mutation?

Accepted Answer

A mutation that increases resistance to malaria in regions where malaria is common

Question 12

Which process interprets the nucleotide 'language' of mRNA into the amino acid sequence of a protein?

Accepted Answer

Translation

Question 13

A mutation that does not change the amino acid sequence of a protein is called:

Accepted Answer

Silent mutation

Question 14

Which of the following is TRUE about the start and stop codons in the genetic code?

Accepted Answer

AUG is the only start codon, and UGA, UAA, and UAG are stop codons.

Question 15

Which of the following best describes a frameshift mutation?

Accepted Answer

A mutation that adds or deletes nucleotides, altering the reading frame

Question 16

Which of the following is NOT a possible consequence of a chromosome-level mutation?

Accepted Answer

Silent mutation

Question 17

Reverse transcriptase is an enzyme that:

Accepted Answer

Synthesizes DNA from an RNA template

Question 18

Which property of the genetic code allows multiple codons to specify the same amino acid?

Accepted Answer

Redundant

Question 19

A scientist observes that a segment of a chromosome is present in multiple copies. This is an example of:

Accepted Answer

Duplication

Question 20

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

Accepted Answer

If several codons specify the same amino acid, the first two bases are usually identical.

How Genes Work: The Molecular Basis of Gene Expression and Mutation

Study Guide - Practice Questions