Question 1

Which of the following best describes the process of transcription in prokaryotes?

Accepted Answer

RNA polymerase synthesizes an RNA strand complementary to the DNA template, starting at the promoter region.

Question 2

During translation in bacteria, which amino acid is incorporated first at the start codon AUG?

Accepted Answer

N-formylmethionine (f-Met)

Question 3

Which of the following statements about mRNA in prokaryotes is correct?

Accepted Answer

mRNA in prokaryotes often contains multiple open reading frames, making it polycistronic.

Question 4

A mutation in the promoter region of a gene most likely affects which step of gene expression?

Accepted Answer

Initiation of transcription

Question 5

Which of the following is a function of chaperone proteins in the cell?

Accepted Answer

They assist in the proper folding and refolding of proteins, especially under stress conditions.

Question 6

Which of the following best explains the role of the sigma factor in bacterial transcription?

Accepted Answer

It recognizes and binds to the promoter region, guiding RNA polymerase to the correct initiation site.

Question 7

A scientist isolates a bacterial mRNA with the following sequence: $5'\,AUG\,GAA\,UUC\,UGA\,3'$. What is the sequence of amino acids produced during translation?

Accepted Answer

Met-Glu-Phe

Question 8

Which of the following is true regarding the differences between prokaryotic and eukaryotic transcription?

Accepted Answer

Eukaryotes require multiple transcription factors for initiation, while prokaryotes use a sigma factor.

Question 9

Which of the following best describes the function of tRNA during translation?

Accepted Answer

tRNA carries amino acids to the ribosome and matches them to the mRNA codon via its anticodon.

Question 10

A bacterial gene is regulated by a Rho-dependent terminator. What would be the effect of a mutation that inactivates the Rho protein?

Accepted Answer

Transcription would fail to terminate at Rho-dependent sites, resulting in abnormally long transcripts.

Question 11

Which of the following is a key feature of the genetic code?

Accepted Answer

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

Question 12

Which of the following best describes the function of the Sec translocase system in bacteria?

Accepted Answer

It exports unfolded proteins and inserts integral membrane proteins into the membrane.

Question 13

A mutation removes the signal sequence from a protein normally secreted by the Tat pathway. What is the most likely outcome?

Accepted Answer

The protein will remain in the cytoplasm and not be exported.

Question 14

Which of the following is a correct pairing of RNA polymerase and its function in eukaryotes?

Accepted Answer

RNA polymerase II synthesizes mRNA.

Question 15

Which of the following is a characteristic of polycistronic mRNA?

Accepted Answer

It contains multiple open reading frames, each encoding a different protein.

Question 16

A researcher is studying a Gram-negative bacterium that secretes toxins into the environment. Which secretion system is most likely involved?

Accepted Answer

Type I-VI secretion systems

Question 17

Which of the following best explains why eukaryotic mRNA requires a 5' cap and a 3' poly(A) tail?

Accepted Answer

To protect the mRNA from degradation and assist in translation initiation.

Question 18

Which of the following is true regarding the directionality of nucleic acid synthesis during replication and transcription?

Accepted Answer

Both DNA and RNA are synthesized in the 5' to 3' direction.

Question 19

A mutation in a bacterial gene causes the encoded protein to be misfolded at low temperatures but not at high temperatures. Which type of chaperone is most likely to assist in refolding this protein?

Accepted Answer

Cold shock proteins

Question 20

Which of the following best describes the function of the anticodon loop of tRNA?

Accepted Answer

It base pairs with the complementary codon on mRNA during translation.

Genetic Information Flow: Replication, Transcription, and Translation

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