Question 1

Which enzyme is responsible for unwinding the parental DNA double helix during DNA replication, as shown in the diagram?

Accepted Answer

Helicase

Question 2

During DNA replication, what is the primary function of single-stranded binding proteins (SSBPs)?

Accepted Answer

To stabilize unwound DNA strands and prevent them from re-annealing

Question 3

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 discontinuously in Okazaki fragments.

Question 4

In the process of RNA splicing, what is the role of the spliceosome?

Accepted Answer

It removes introns and joins exons to produce mature mRNA.

Question 5

Which of the following statements about gene expression in eukaryotes is correct?

Accepted Answer

Transcription occurs in the nucleus, and translation occurs in the cytoplasm.

Question 6

Which enzyme is responsible for synthesizing short RNA primers during DNA replication?

Accepted Answer

Primase

Question 7

What is the function of DNA ligase during DNA replication?

Accepted Answer

It joins Okazaki fragments by forming phosphodiester bonds.

Question 8

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

Accepted Answer

DNA polymerase can only synthesize DNA in the 5' → 3' direction, so the lagging strand is synthesized in short segments.

Question 9

Which of the following modifications occurs to eukaryotic pre-mRNA before it becomes mature mRNA?

Accepted Answer

All of the above

Question 10

A mutation prevents the removal of introns from pre-mRNA. What is the most likely consequence?

Accepted Answer

The mRNA will contain non-coding sequences, potentially resulting in a nonfunctional protein.

Question 11

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

Accepted Answer

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

Question 12

Which process is depicted in the second image, and what is its biological significance?

Accepted Answer

RNA splicing; it removes introns and joins exons to produce mature mRNA.

Question 13

Which of the following statements about Okazaki fragments is correct?

Accepted Answer

They are joined together by DNA ligase to form a continuous DNA strand.

Question 14

Which of the following best describes the flow of genetic information in eukaryotic cells, as shown in the third image?

Accepted Answer

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

Question 15

Which of the following is NOT a function of the spliceosome?

Accepted Answer

Addition of a poly-A tail to mRNA

Question 16

Which enzyme is responsible for relieving supercoiling ahead of the replication fork during DNA replication?

Accepted Answer

Topoisomerase (DNA gyrase)

Question 17

If a mutation in a eukaryotic cell prevents the addition of the 5' cap to mRNA, what is the most likely outcome?

Accepted Answer

The mRNA will be rapidly degraded and translation efficiency will decrease.

Question 18

Which of the following statements about the central dogma of molecular biology is correct?

Accepted Answer

DNA is transcribed into RNA, which is then translated into protein.

Question 19

Which of the following is a direct result of the process shown in the first image (DNA replication)?

Accepted Answer

Two identical DNA molecules, each with one parental and one newly synthesized strand.

Question 20

Which of the following is true regarding the removal of introns during RNA processing?

Accepted Answer

Introns are removed by the spliceosome during RNA processing.

Comprehensive Study Notes: Genetic Mapping, DNA Replication, Gene Expression, and Regulation

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