Question 1

Which of the following statements best describes the main structural difference between RNA and DNA?

Accepted Answer

RNA is usually single-stranded and can form complex secondary and tertiary structures, while DNA is typically double-stranded and forms a regular helix.

Question 2

Which of the following modifications occurs at the 5' end of eukaryotic mRNA during processing?

Accepted Answer

Addition of a 7-methylguanosine cap

Question 3

What is the function of the 3' poly(A) tail in eukaryotic mRNA?

Accepted Answer

It protects mRNA from degradation and assists in export from the nucleus.

Question 4

Which of the following best describes the role of tRNA in protein synthesis?

Accepted Answer

tRNA brings specific amino acids to the ribosome by matching its anticodon with the codon on mRNA.

Question 5

Which of the following is a unique feature of eukaryotic tRNA processing compared to bacterial tRNA processing?

Accepted Answer

Splicing of a 14-nucleotide intron

Question 6

Which rRNA molecules are found in the large ribosomal subunit of eukaryotes?

Accepted Answer

5S, 5.8S, and 28S

Question 7

A mutation prevents the addition of the CCA sequence to the 3' end of tRNA. What is the most likely consequence?

Accepted Answer

The tRNA will not be able to attach to its specific amino acid.

Question 8

Which of the following best describes the function of rRNA in the ribosome?

Accepted Answer

It acts as a catalyst for peptide bond formation during translation.

Question 9

Which of the following regulatory non-coding RNAs is primarily involved in gene silencing through mRNA degradation or translation suppression?

Accepted Answer

miRNA

Question 10

Which of the following statements about prokaryotic and eukaryotic mRNA is correct?

Accepted Answer

Prokaryotic mRNA can be translated immediately after transcription, while eukaryotic mRNA requires processing.

Question 11

Which of the following is a function of long non-coding RNAs (lncRNAs)?

Accepted Answer

They regulate gene expression at transcriptional and post-transcriptional levels.

Question 12

Which of the following best describes the role of the 16S rRNA in prokaryotic ribosomes?

Accepted Answer

It is part of the small ribosomal subunit and is involved in mRNA binding and decoding.

Question 13

Which of the following small non-coding RNAs is involved in the chemical modification of rRNA and tRNA?

Accepted Answer

snoRNA

Question 14

A patient has a mutation in the gene encoding the telomerase RNA component (TERC). Which cellular process is most likely to be affected?

Accepted Answer

Telomere elongation

Question 15

Which of the following best describes the function of the RNA-induced silencing complex (RISC)?

Accepted Answer

It degrades target mRNA or suppresses its translation in response to siRNA or miRNA binding.

Question 16

Which of the following is true regarding the structure of tRNA?

Accepted Answer

tRNA contains an anticodon loop that pairs with the mRNA codon and a 3' CCA end that binds an amino acid.

Question 17

Which of the following is a function of PIWI-interacting RNAs (piRNAs)?

Accepted Answer

They regulate gene expression at the transcriptional and translational level, especially in germ cells.

Question 18

Which of the following best explains why eukaryotic mRNA must be processed before translation?

Accepted Answer

Eukaryotic mRNA contains introns that must be removed, and requires a 5' cap and 3' poly(A) tail for stability and export.

Question 19

Which of the following is the correct sequence of events in eukaryotic gene expression from DNA to protein?

Accepted Answer

Transcription → RNA processing → Translation

RNA Structure, Function, and Types in Biochemistry

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