Question 1

Which of the following best explains why DNA replication is described as 'semiconservative'?

Accepted Answer

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

Question 2

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

Accepted Answer

DNA helicase

Question 3

A DNA molecule is found to contain 35% adenine (A). According to Chargaff's rules, what percentage of guanine (G) would you expect to find?

Accepted Answer

$$15\%$$

Question 4

Which of the following statements about the directionality of nucleic acid strands is correct?

Accepted Answer

DNA strands are synthesized from the 5' end to the 3' end.

Question 5

Which type of bond connects nucleotides within a single strand of DNA?

Accepted Answer

Phosphodiester bonds

Question 6

Why is a DNA helix with mostly A-T base pairs easier to separate than one with mostly G-C pairs?

Accepted Answer

A-T pairs are held together by two hydrogen bonds, while G-C pairs are held together by three hydrogen bonds.

Question 7

What is the primary function of DNA ligase during DNA replication?

Accepted Answer

To join Okazaki fragments on the lagging strand

Question 8

If a mutation introduced an additional origin of replication (ORI) in a prokaryotic chromosome, what would be the most likely effect?

Accepted Answer

DNA replication would occur more rapidly.

Question 9

Which of the following is NOT a component of a nucleotide?

Accepted Answer

A carboxyl group

Question 10

Which of the following best describes the difference between DNA and RNA nucleotides?

Accepted Answer

DNA nucleotides contain deoxyribose; RNA nucleotides contain ribose.

Question 11

Which of the following is a function of RNA in cells?

Accepted Answer

Speeding up chemical reactions as ribozymes

Question 12

During DNA replication, why must the two strands of the DNA helix be separated?

Accepted Answer

So that each strand can serve as a template for the synthesis of a new complementary strand.

Question 13

Which of the following best describes the role of an RNA primer in DNA replication?

Accepted Answer

It provides a starting point for DNA polymerase to begin synthesis.

Question 14

Which of the following statements about DNA polymerase is FALSE?

Accepted Answer

It can initiate DNA synthesis without a primer.

Question 15

Which of the following is a correct pairing of nitrogenous bases in DNA?

Accepted Answer

Adenine pairs with thymine

Question 16

Which of the following best explains why DNA polymerases are highly accurate during DNA replication?

Accepted Answer

They have proofreading activity that removes and replaces incorrect nucleotides.

Question 17

Which of the following is a real-world consequence of errors in DNA replication that are not corrected?

Accepted Answer

Mutations may occur, potentially leading to diseases such as cancer.

Question 18

Which of the following is true about the replication of eukaryotic chromosomes?

Accepted Answer

Replication starts at multiple origins of replication.

Question 19

Which of the following best describes the antiparallel nature of DNA?

Accepted Answer

One strand runs 5' to 3', and the other runs 3' to 5'.

Question 20

A scientist isolates an RNA molecule and finds that 35% of its nucleotides are adenine (A). What can be concluded about the percentage of uracil (U)?

Accepted Answer

It cannot be determined without additional information.

DNA Structure, Replication, and Repair: Study Notes for General Biology

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