Question 1

Which enzyme is responsible for extending the RNA primer by adding nucleotides to the 3' end during DNA replication?

Accepted Answer

DNA polymerase

Question 2

What is the evolutionary significance of mutations in DNA?

Accepted Answer

They are the source of genetic variation upon which natural selection operates.

Question 3

During DNA replication, which enzyme seals the sugar-phosphate backbone between Okazaki fragments?

Accepted Answer

Ligase

Question 4

Why do eukaryotic chromosomes have telomeres?

Accepted Answer

To postpone the erosion of genes near the ends of DNA molecules.

Question 5

Which process describes the synthesis of RNA using information in DNA?

Accepted Answer

Transcription

Question 6

In eukaryotes, what separates transcription from translation?

Accepted Answer

The nuclear envelope

Question 7

Which repair mechanism involves a nuclease cutting out and replacing damaged stretches of DNA?

Accepted Answer

Nucleotide excision repair

Question 8

What is the role of telomerase in germ cells?

Accepted Answer

It catalyzes the lengthening of telomeres.

Question 9

Which of the following best describes the Central Dogma of molecular biology?

Accepted Answer

DNA → RNA → Protein

Question 10

In prokaryotes, when does translation of mRNA begin?

Accepted Answer

Before transcription has finished

Question 11

Which sequence signals the end of transcription in bacteria?

Accepted Answer

Terminator

Question 12

What is the function of single-stranded binding proteins (SSBPs) during DNA replication?

Accepted Answer

They protect and keep single-stranded DNA separated.

Question 13

Which of the following is true about RNA polymerase during transcription?

Accepted Answer

It synthesizes RNA complementary to the DNA template strand.

Question 14

What is the consequence of repeated rounds of DNA replication in linear chromosomes?

Accepted Answer

DNA molecules become shorter with uneven ends.

Question 15

Which stage of transcription involves RNA polymerase moving along the DNA and adding nucleotides to the growing RNA molecule?

Accepted Answer

Elongation

Question 16

A mutation in the gene for pigmentation results in a change in phenotype because:

Accepted Answer

The mutation alters the mRNA and the protein required for pigment synthesis does not work.

Question 17

Which of the following is a correct base-pairing rule for RNA during transcription?

Accepted Answer

A pairs with U

Question 18

What is the role of transcription factors in eukaryotic transcription initiation?

Accepted Answer

They help guide the binding of RNA polymerase to the promoter.

Question 19

Which enzyme relieves the supercoiling tension ahead of the replication fork?

Accepted Answer

Topoisomerase

Question 20

In eukaryotes, what sequence is transcribed to signal the end of transcription?

Accepted Answer

Polyadenylation signal sequence

DNA Replication, Proofreading, Telomeres, and Transcription: Study Notes for General Biology

Study Guide - Practice Questions