Question 1

Which of the following best describes the flow of genetic information according to the Central Dogma of molecular biology?

Accepted Answer

DNA → RNA → Protein

Question 2

During transcription, which strand of DNA is used as the template for mRNA synthesis, and in which direction is the template strand read?

Accepted Answer

Template strand; 3' → 5'

Question 3

What is the primary function of the promoter region in a gene?

Accepted Answer

It signals where transcription should begin.

Question 4

Which of the following modifications occur to eukaryotic mRNA before it leaves the nucleus?

Accepted Answer

Addition of a 5' cap, splicing of introns, and addition of a poly(A) tail

Question 5

Alternative splicing allows a single gene to:

Accepted Answer

Produce multiple different proteins

Question 6

Which of the following sequences is removed from the pre-mRNA during processing and does NOT exit the nucleus?

Accepted Answer

Introns

Question 7

A mutation in the promoter region of a gene would most likely affect:

Accepted Answer

The initiation of transcription

Question 8

Which enzyme catalyzes the synthesis of mRNA from a DNA template?

Accepted Answer

RNA polymerase

Question 9

If the template DNA strand has the sequence 3'-TACGGTACG-5', what is the sequence of the mRNA produced?

Accepted Answer

5'-AUGCCAUGC-3'

Question 10

Which of the following statements about gene expression in multicellular organisms is TRUE?

Accepted Answer

All cells contain the same DNA, but express different genes.

Question 11

Which of the following best explains why a neuron and a liver cell in the same individual can look and function differently?

Accepted Answer

They express different sets of genes.

Question 12

Transcription factors are proteins that:

Accepted Answer

Bind to the promoter region to regulate transcription

Question 13

Which of the following is TRUE regarding the polarity of nucleic acids during transcription?

Accepted Answer

The template DNA strand is read 3' → 5', and mRNA is synthesized 5' → 3'

Question 14

Which of the following events occurs LAST during the process of transcription in eukaryotes?

Accepted Answer

Addition of the poly(A) tail

Question 15

A scientist discovers a mutation that prevents the addition of a 5' cap to mRNA. Which of the following is a likely consequence?

Accepted Answer

The mRNA will be rapidly degraded and poorly translated.

Question 16

Which of the following best describes the relationship between the coding strand of DNA and the mRNA transcript?

Accepted Answer

They are identical except that mRNA has U instead of T.

Question 17

Which of the following is NOT a function of the poly(A) tail added to eukaryotic mRNA?

Accepted Answer

Coding for amino acids in the protein

Question 18

Which of the following statements about transcription in eukaryotes is FALSE?

Accepted Answer

Both DNA strands are used as templates for the same gene.

Question 19

A gene contains the following sequence on its template strand: 3'-TACGCTAGC-5'. What is the sequence of the coding strand, and what would be the corresponding mRNA sequence?

Accepted Answer

Coding strand: 5'-ATGCGATCG-3'; mRNA: 5'-AUGCGAUCG-3'

Question 20

Which of the following best explains why changes in DNA sequence can affect protein function?

Accepted Answer

DNA sequence determines the sequence of mRNA, which determines the sequence of amino acids in the protein.

Transcription and Gene Expression: Structure, Function, and Regulation

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