Question 1

Which of the following statements best describes the direction in which DNA polymerases synthesize new DNA strands?

Accepted Answer

DNA polymerases synthesize new DNA strands in the 5' to 3' direction.

Question 2

What is the role of primase during DNA replication?

Accepted Answer

Primase synthesizes short RNA primers that provide a starting point for DNA polymerase.

Question 3

If the template DNA strand has the sequence 3'-TACGGTAC-5', what is the sequence of the newly synthesized complementary DNA strand?

Accepted Answer

5'-ATGCCATG-3'

Question 4

Which enzyme is primarily responsible for elongating the new DNA strand in prokaryotes?

Accepted Answer

DNA Polymerase III

Question 5

Why is an RNA primer necessary for DNA polymerase to begin synthesis of a new DNA strand?

Accepted Answer

DNA polymerase can only add nucleotides to an existing 3' hydroxyl group.

Question 6

Which of the following best explains why DNA polymerase cannot synthesize DNA in the 3' to 5' direction?

Accepted Answer

The active site of DNA polymerase only accommodates the 5' phosphate of incoming nucleotides.

Question 7

A mutation in the gene encoding primase would most likely result in which of the following outcomes during DNA replication?

Accepted Answer

No RNA primers would be synthesized, preventing DNA polymerase from starting DNA synthesis.

Question 8

Which of the following is a requirement for all DNA polymerases during DNA replication?

Accepted Answer

A single-stranded DNA template and an RNA primer with a free 3' OH group.

Question 9

During DNA replication, what happens to the RNA primers after they have served their purpose?

Accepted Answer

They are converted into DNA and replaced by DNA nucleotides.

Question 10

A scientist is studying a new organism and finds that its DNA polymerase can add nucleotides without a primer. What would be the most significant implication of this finding?

Accepted Answer

The organism's DNA replication process does not require primase.

Question 11

If a DNA strand has the sequence 5'-GGCATTA-3', what is the complementary sequence synthesized by DNA polymerase?

Accepted Answer

3'-CCGTAAT-5'

Question 12

Which of the following best describes the function of DNA Polymerase III in prokaryotes?

Accepted Answer

It synthesizes the majority of the new DNA strand during replication.

Question 13

A student claims that DNA polymerase can initiate DNA synthesis without any primer. Which evidence contradicts this claim?

Accepted Answer

DNA polymerase requires a free 3' OH group provided by an RNA primer to begin synthesis.

Question 14

Which of the following is NOT a function of DNA polymerase during DNA replication?

Accepted Answer

Adding RNA primers to the template strand.

Question 15

In a DNA replication experiment, a researcher observes that new DNA strands are not being synthesized. Which of the following is the most likely explanation?

Accepted Answer

The RNA primers were not synthesized, so DNA polymerase could not begin DNA synthesis.

DNA Polymerases: Structure, Function, and Mechanism

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