Question 1

Which of the following best describes the central dogma of molecular biology?

Accepted Answer

Information flows from DNA to RNA to protein.

Question 2

During DNA replication in bacteria, which enzyme is responsible for synthesizing the RNA primer?

Accepted Answer

Primase

Question 3

Which of the following statements about the structure of DNA is correct?

Accepted Answer

Adenine pairs with thymine via two hydrogen bonds.

Question 4

Which of the following is a key difference between prokaryotic and eukaryotic gene expression?

Accepted Answer

Prokaryotic mRNA translation can begin before transcription is complete.

Question 5

Which of the following best describes the function of DNA polymerase III during DNA replication?

Accepted Answer

Synthesizes the leading and lagging DNA strands in the 5' to 3' direction.

Question 6

A mutation causes the loss of exonuclease activity in DNA polymerase III. What is the most likely consequence?

Accepted Answer

Decreased ability to proofread and correct mismatched bases.

Question 7

Which of the following sequences would be transcribed into the RNA sequence $$5'	ext{GCUAUGCGAU}\ 3'$$?

Accepted Answer

$3'	ext{CGAUACGCUA}\ 5'$$

Question 8

Which of the following is true regarding the genetic code?

Accepted Answer

The code is degenerate, meaning multiple codons can specify the same amino acid.

Question 9

In the regulation of the lac operon, what happens when both glucose and lactose are present?

Accepted Answer

The operon is repressed due to the presence of glucose.

Question 10

Which of the following best describes an inducible enzyme?

Accepted Answer

It is produced only when its substrate is present.

Question 11

Which of the following is a function of the 5' cap added to eukaryotic mRNA?

Accepted Answer

It stabilizes the mRNA and enhances translation.

Question 12

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.

Question 13

Which of the following is NOT a function of tRNA during translation?

Accepted Answer

Synthesizing peptide bonds between amino acids.

Question 14

Which of the following mechanisms is unique to eukaryotic gene regulation?

Accepted Answer

Modification of chromosome structure to regulate gene expression.

Question 15

A bacterium is grown in a medium containing both glucose and lactose. Which of the following best describes the pattern of gene expression for the lac operon?

Accepted Answer

The lac operon is repressed until glucose is depleted, then induced.

Question 16

Which of the following is the correct sequence of events during bacterial transcription?

Accepted Answer

Initiation, elongation, termination

Question 17

Which of the following statements about repressible enzymes is correct?

Accepted Answer

They are produced routinely but can be turned off when not needed.

Question 18

Which of the following best describes the role of the operator in bacterial gene regulation?

Accepted Answer

It is the DNA sequence where repressors bind to block transcription.

Question 19

Which of the following is a consequence of catabolite repression in bacteria?

Accepted Answer

Preferential use of glucose over other sugars.

Question 20

Which of the following is true regarding the process of translation in prokaryotes?

Accepted Answer

Translation and transcription are coupled, occurring simultaneously.

Central Dogma, DNA Replication, Transcription, Translation, and Gene Regulation in Microbiology

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