Q: Which of the following base pairing rules is correct according to Chargaff’s rules?

$$\text{A} = \text{T}$$ and $$\text{C} = \text{G}$$

Question 1

Which enzyme is primarily responsible for relieving the tension caused by DNA supercoiling ahead of the replication fork during DNA replication?

Accepted Answer

Topoisomerase (DNA gyrase)

Question 2

During DNA replication, which strand is synthesized continuously in the same direction as the replication fork movement?

Accepted Answer

Leading strand

Question 3

Which of the following statements best describes the Meselson-Stahl experiment's conclusion about DNA replication?

Accepted Answer

DNA replication is semiconservative, with each new DNA molecule containing one old and one new strand.

Question 4

Which of the following is NOT a requirement for DNA polymerase activity during DNA replication?

Accepted Answer

A promoter sequence

Question 5

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

Reannealing of separated DNA strands, preventing replication

Question 6

Which of the following best explains why Okazaki fragments are formed during DNA replication?

Accepted Answer

The lagging strand is synthesized discontinuously in short segments due to the antiparallel nature of DNA.

Question 7

Which of the following base pairing rules is correct according to Chargaff’s rules?

Accepted Answer

$$	ext{A} = 	ext{T}$$ and $$	ext{C} = 	ext{G}$$

Question 8

Which of the following is a key difference between DNA and RNA?

Accepted Answer

RNA contains ribose sugar, while DNA contains deoxyribose sugar.

Question 9

Which enzyme is responsible for joining Okazaki fragments on the lagging strand during DNA replication?

Accepted Answer

DNA ligase

Question 10

A patient’s cells are found to have abnormally short telomeres and reduced telomerase activity. Which of the following is the most likely consequence?

Accepted Answer

Premature cellular aging and loss of cell function

Question 11

Which of the following best describes the function of primase during DNA replication?

Accepted Answer

It synthesizes short RNA primers to provide a starting point for DNA polymerase.

Question 12

Which of the following is true regarding the directionality of DNA synthesis?

Accepted Answer

DNA is synthesized in the 5' to 3' direction.

Question 13

Which of the following is a function of DNA polymerase I in prokaryotic DNA replication?

Accepted Answer

Replacing RNA primers with DNA nucleotides

Question 14

Which of the following statements about transcription is correct?

Accepted Answer

RNA polymerase synthesizes RNA in the 5' to 3' direction using a DNA template.

Question 15

Which of the following is a real-world example of a single nucleotide polymorphism (SNP) affecting human physiology?

Accepted Answer

Lactose tolerance

Question 16

Which of the following best describes the role of telomerase in eukaryotic cells?

Accepted Answer

It extends the telomeres at the ends of chromosomes, preventing their shortening.

Question 17

Which of the following is a key difference between prokaryotic and eukaryotic DNA replication origins?

Accepted Answer

Eukaryotes have multiple origins of replication per chromosome.

Question 18

Which of the following best explains why DNA polymerase has a lower error rate than RNA polymerase?

Accepted Answer

DNA polymerase has 3' to 5' exonuclease proofreading activity.

Question 19

Which of the following is a correct description of the flow of genetic information in a cell?

Accepted Answer

$$	ext{DNA} ightarrow 	ext{RNA} ightarrow 	ext{Protein}$$

Question 20

A mutation that disables the proofreading function of DNA polymerase would most likely result in which of the following?

Accepted Answer

An increase in permanent DNA mutations

Foundations of Genetics: From Classical Principles to Molecular Mechanisms

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