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

Question 1

Which experiment led to the formulation of the one-gene, one-enzyme hypothesis?

Accepted Answer

Beadle and Tatum's irradiation of bread mold N. crassa and analysis of mutants unable to synthesize certain compounds

Question 2

What is the central dogma of molecular biology?

Accepted Answer

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

Question 3

Which of the following best describes a codon?

Accepted Answer

A group of three bases that specifies a particular amino acid

Question 4

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

Accepted Answer

Nonsense mutation

Question 5

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

Accepted Answer

RNA polymerase

Question 6

What is the effect of a frameshift mutation?

Accepted Answer

It shifts the reading frame, altering the meaning of all subsequent codons

Question 7

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

Accepted Answer

Each codon can code for more than one amino acid

Question 8

A scientist observes a segment of a chromosome that has broken off, flipped around, and rejoined. What type of mutation is this?

Accepted Answer

Inversion

Question 9

Which of the following best explains why silent mutations do not affect the phenotype?

Accepted Answer

The genetic code is redundant, so some codons code for the same amino acid

Question 10

Which process interprets the nucleotide 'language' of mRNA into amino acids?

Accepted Answer

Translation

Question 11

A mutation that increases an organism's ability to survive and reproduce is called:

Accepted Answer

Beneficial mutation

Question 12

Which of the following is a real-world example of a chromosome-level mutation?

Accepted Answer

A segment of chromosome 21 is present in three copies, resulting in Down syndrome

Question 13

Which of the following is NOT a property of the genetic code?

Accepted Answer

Ambiguous

Question 14

If a DNA template strand has the sequence $$3'	ext{-TACGGTACC-}5'$$, what is the corresponding mRNA sequence?

Accepted Answer

$$5'	ext{-AUGCCAUGG-}3'$$

Question 15

Which of the following best describes the relationship between genotype and phenotype?

Accepted Answer

Genotype determines the sequence of mRNA, which determines the sequence of proteins, which determines phenotype

Question 16

Which of the following is an example of a missense mutation?

Accepted Answer

A codon change from GAA (glutamic acid) to GUA (valine)

Question 17

Which of the following is TRUE about the flow of genetic information in retroviruses?

Accepted Answer

Information flows from RNA to DNA using reverse transcriptase

Question 18

A scientist observes that a segment of a chromosome is present in multiple copies. What type of mutation is this?

Accepted Answer

Duplication

Question 19

Which of the following is a consequence of a frameshift mutation in a gene coding region?

Accepted Answer

All amino acids downstream of the mutation are likely to be altered

Question 20

Which of the following statements about alleles is correct?

Accepted Answer

Alleles of the same gene differ in their DNA sequence

How Genes Work: From DNA to Protein and Mutation

Study Guide - Practice Questions