Question 1

Which experiment provided the first direct evidence that DNA, and not protein, is the genetic material responsible for heredity in bacteriophages?

Accepted Answer

Alfred Hershey and Martha Chase's blender experiment with T2 phages and E. coli

Question 2

Rosalind Franklin's X-ray diffraction images of DNA were critical in helping Watson and Crick deduce which aspect of DNA structure?

Accepted Answer

The double helical structure and consistent width of the molecule

Question 3

According to Chargaff's rules, if a DNA sample contains 30% adenine, what percentage of guanine would you expect to find?

Accepted Answer

$$20\%$$

Question 4

Which of the following best describes the semiconservative model of DNA replication as demonstrated by Meselson and Stahl?

Accepted Answer

Each daughter DNA molecule consists of one parental and one newly synthesized strand.

Question 5

During DNA replication, why is the synthesis of the lagging strand discontinuous?

Accepted Answer

DNA polymerase can only add nucleotides to the 3’ end, and the two template strands are antiparallel.

Question 6

Which enzyme is responsible for joining Okazaki fragments together during DNA replication?

Accepted Answer

DNA ligase

Question 7

A mutation in the gene encoding single-stranded binding proteins (SSBs) would most likely result in which of the following problems during DNA replication?

Accepted Answer

The DNA strands would re-anneal before replication could proceed.

Question 8

Which of the following best explains why topoisomerase is essential during DNA replication in eukaryotic cells?

Accepted Answer

It relieves the tension caused by unwinding of the DNA double helix.

Question 9

Which of the following statements about the antiparallel structure of DNA is correct?

Accepted Answer

One DNA strand runs 5’ to 3’ and the other runs 3’ to 5’.

Question 10

Which of the following best describes a nucleosome?

Accepted Answer

A segment of DNA wrapped around a core of histone proteins

Question 11

A scientist observes that after two rounds of DNA replication in the presence of $$^{15}N$$ and $$^{14}N$$, the DNA molecules consist of both intermediate and light bands. Which replication model does this observation support?

Accepted Answer

Semiconservative

Question 12

Which of the following is the correct base-pairing rule for DNA?

Accepted Answer

A pairs with T, G pairs with C

Question 13

Which enzyme is responsible for unwinding the DNA double helix at the replication fork?

Accepted Answer

Helicase

Question 14

In a eukaryotic cell, which of the following best describes the structure of chromatin during interphase?

Accepted Answer

Loosely packed, allowing access for transcription

Question 15

Which of the following best explains the significance of Okazaki fragments in DNA replication?

Accepted Answer

They enable the lagging strand to be synthesized in short segments due to the antiparallel nature of DNA.

Question 16

A patient is found to have a mutation that impairs the function of DNA polymerase. Which of the following cellular processes would be most directly affected?

Accepted Answer

Replication of DNA

Question 17

Which scientist(s) demonstrated that the 'transforming principle' in bacteria was DNA by using enzymes to selectively degrade proteins, RNA, and DNA?

Accepted Answer

Oswald Avery, Maclyn McCarty, and Colin MacLeod

Question 18

Which of the following best describes the role of primers in DNA replication?

Accepted Answer

They provide a starting point with a free 3’ hydroxyl group for DNA polymerase to begin synthesis.

Question 19

A researcher is studying a DNA molecule with the following sequence on one strand: 5’-ATCGGCTA-3’. What is the complementary sequence on the other strand?

Accepted Answer

3’-TAGCCGAT-5’

Question 20

Which of the following best explains why DNA replication is highly accurate?

Accepted Answer

DNA polymerase proofreads and corrects errors during synthesis.

The Molecular Basis of Inheritance: DNA Structure, Replication, and Chromatin Organization

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드