Question 1

Which of the following is NOT a characteristic of hereditary material?

Accepted Answer

It is unable to accurately replicate itself.

Question 2

Which experiment provided direct evidence that DNA is the transformation factor responsible for heredity?

Accepted Answer

Avery, MacLeod, and McCarty's in vitro transformation experiment.

Question 3

In the Hershey-Chase experiment, which molecule was shown to be responsible for bacteriophage infection of bacteria?

Accepted Answer

DNA

Question 4

Which base pairs are complementary in the DNA double helix?

Accepted Answer

A pairs with T, G pairs with C

Question 5

What is the significance of the major and minor grooves in the DNA double helix?

Accepted Answer

They are regions where DNA binding proteins make direct contact with nucleotides.

Question 6

Which form of DNA is most commonly found in cells and has a right-handed twist?

Accepted Answer

B-form

Question 7

What is the outcome of semiconservative DNA replication?

Accepted Answer

Each daughter duplex contains one parental and one daughter strand.

Question 8

In the Meselson-Stahl experiment, what was the purpose of using cesium chloride (CsCl) centrifugation?

Accepted Answer

To separate molecules with slightly different molecular weights.

Question 9

Which sequence is most commonly found at the origin of replication (oriC) in E. coli?

Accepted Answer

TTATCC

Question 10

What is the role of DnaA protein during DNA replication initiation in E. coli?

Accepted Answer

It binds the 9-mer sequences, bends DNA, and breaks hydrogen bonds in the A-T rich 13-mer region.

Question 11

Why are RNA primers necessary for DNA replication?

Accepted Answer

DNA polymerase can only elongate a strand from the 3' end of a preexisting strand.

Question 12

Which enzyme removes RNA primers and replaces them with DNA nucleotides during replication in E. coli?

Accepted Answer

DNA polymerase I

Question 13

What is the function of single-stranded binding protein (SSB) during DNA replication?

Accepted Answer

It prevents unwound DNA strands from reannealing.

Question 14

Which strand is synthesized continuously during DNA replication?

Accepted Answer

Leading strand

Question 15

What is the role of DNA ligase in DNA replication?

Accepted Answer

It seals the gap among DNA fragments after primer removal.

Question 16

Which of the following best describes the directionality of DNA replication in bacterial chromosomes?

Accepted Answer

Bidirectional from a single origin

Question 17

In eukaryotic cells, what is the name given to the multiple origins of replication found throughout the genome?

Accepted Answer

Autonomously replicating sequences (ARS)

Question 18

Which of the following equations correctly represents the antiparallel nature of DNA strands?

Accepted Answer

$$5' \rightarrow 3'$$ and $$3' \rightarrow 5'$$

Question 19

If a bacterial cell has a mutation in the gene encoding DnaB, which process would be most directly affected?

Accepted Answer

Unwinding of the DNA helix

Question 20

Which of the following best explains why DNA is considered mutable?

Accepted Answer

It undergoes a low rate of mutations that introduces genetic variation.

DNA Structure and Replication: Foundations of Genetic Material

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