Question 1

Which of the following best explains why dogs can have different coat colors?

Accepted Answer

Different proteins in the papilla cells are coded by alleles at specific gene loci, resulting in varied pigment expression.

Question 2

During DNA replication, which enzyme is responsible for unwinding the double helix?

Accepted Answer

Helicase

Question 3

What is the role of single-stranded binding proteins during DNA replication?

Accepted Answer

They stabilize the unwound DNA strands and prevent them from re-annealing.

Question 4

Which statement correctly describes the directionality of DNA synthesis?

Accepted Answer

DNA is synthesized in the $$5' \rightarrow 3'$$ direction.

Question 5

What is the function of the 3' hydroxyl group during DNA replication?

Accepted Answer

It serves as the attachment point for incoming nucleotides, allowing DNA polymerase to extend the chain.

Question 6

Which enzyme synthesizes the RNA primer required for DNA polymerase to begin extension?

Accepted Answer

Primase

Question 7

Why is DNA replication considered an endergonic process?

Accepted Answer

It requires energy input, which is provided by the hydrolysis of nucleoside triphosphates.

Question 8

Which of the following best describes the difference between the leading and lagging strands during DNA replication?

Accepted Answer

The leading strand is synthesized continuously, while the lagging strand is synthesized in short fragments called Okazaki fragments.

Question 9

What is the role of DNA ligase during DNA replication?

Accepted Answer

It joins Okazaki fragments together by forming phosphodiester bonds.

Question 10

A mutation occurs during DNA replication and is not repaired. Which of the following outcomes is most likely?

Accepted Answer

The mutation can be inherited if it occurs in germ line cells.

Question 11

Which enzyme removes RNA primers and replaces them with DNA during replication?

Accepted Answer

DNA polymerase I

Question 12

In the context of PCR (Polymerase Chain Reaction), which of the following is required to initiate DNA synthesis?

Accepted Answer

A short DNA primer complementary to the target sequence

Question 13

Which of the following best describes the relationship between PCR and natural DNA replication?

Accepted Answer

PCR mimics natural DNA replication by using primers and DNA polymerase to amplify specific DNA sequences in vitro.

Question 14

A student is studying a mutation in a dog’s coat color gene. Which term best describes the different versions of this gene that may result in different coat colors?

Accepted Answer

Allele

Question 15

Which of the following is a direct consequence of a proofreading enzyme failing to correct a mismatch during DNA replication?

Accepted Answer

A permanent mutation may be passed to daughter cells.

Question 16

Which bond is formed between adjacent nucleotides during DNA synthesis?

Accepted Answer

Phosphodiester bond

Question 17

During DNA replication, which molecule provides the energy required for the addition of nucleotides?

Accepted Answer

Nucleoside triphosphates (e.g., dATP, dGTP, dCTP, dTTP)

Question 18

Which of the following steps occurs first during DNA replication?

Accepted Answer

Unwinding of the DNA helix by helicase

Question 19

A researcher is designing a PCR experiment to amplify a gene. Which of the following must be true about the primers used?

Accepted Answer

Primers must be complementary to the sequences flanking the target region.

Question 20

Which of the following best explains why DNA polymerase cannot initiate synthesis on a single-stranded DNA template without a primer?

Accepted Answer

DNA polymerase requires a free $$3'-OH $$group to add nucleotides.

DNA Replication and Genetic Terminology: Structure, Function, and Laboratory Applications

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