Question 1

Which of the following best describes the function of the 5′ cap added to eukaryotic pre-mRNA during RNA processing?

Accepted Answer

It facilitates the export of mRNA from the nucleus and helps ribosomes attach to the mRNA.

Question 2

What is the main consequence of removing the 5′ cap from mature mRNA molecules in a eukaryotic cell?

Accepted Answer

The mRNA will be rapidly degraded by hydrolytic enzymes.

Question 3

Which sequence signals the addition of the poly-A tail to the 3′ end of a pre-mRNA molecule?

Accepted Answer

AAUAAA

Question 4

During RNA splicing, what is the fate of introns in a typical eukaryotic gene?

Accepted Answer

They are cut out and degraded.

Question 5

Which of the following statements about exons is correct?

Accepted Answer

Exons are sequences that remain in the mature mRNA after splicing.

Question 6

Alternative RNA splicing allows a single gene to:

Accepted Answer

Encode multiple polypeptides by including or excluding different exons.

Question 7

Which complex is responsible for removing introns from pre-mRNA in eukaryotic cells?

Accepted Answer

Spliceosome

Question 8

Which of the following is NOT a function of the poly-A tail?

Accepted Answer

Coding for the stop codon

Question 9

Ribozymes are unique because they:

Accepted Answer

Are RNA molecules that function as enzymes.

Question 10

Which property of RNA allows ribozymes to catalyze reactions?

Accepted Answer

RNA can form complex three-dimensional structures through base pairing.

Question 11

A mutation that disrupts the polyadenylation signal (AAUAAA) in a gene would most likely result in:

Accepted Answer

Failure to add a poly-A tail, leading to unstable mRNA.

Question 12

If a eukaryotic cell lacked functional spliceosomes, what would be the most direct consequence?

Accepted Answer

Pre-mRNA would retain introns, resulting in abnormal proteins.

Question 13

Which of the following best explains why humans can produce more proteins than the number of genes they possess?

Accepted Answer

Alternative RNA splicing allows different combinations of exons to be joined.

Question 14

Which region of a mature mRNA is NOT translated into protein but is important for ribosome binding and regulation?

Accepted Answer

5′ UTR

Question 15

A scientist discovers an RNA molecule that can catalyze its own splicing without any proteins. This molecule is best described as a:

Accepted Answer

Ribozyme

Question 16

Which of the following steps occurs LAST during the processing of a eukaryotic pre-mRNA?

Accepted Answer

Splicing of introns

Question 17

If a mutation caused all exons to be removed during RNA processing, what would be the result?

Accepted Answer

A mature mRNA with only introns, unable to code for a functional protein.

Question 18

Which of the following is a direct result of the single-stranded nature of RNA?

Accepted Answer

RNA can base-pair with itself to form complex shapes necessary for catalysis.

Question 19

In the analogy of watching a pre-recorded TV show, what do introns correspond to?

Accepted Answer

Commercial breaks that are skipped during playback

Question 20

Which of the following best describes the role of small RNAs in the spliceosome?

Accepted Answer

They help recognize splice sites and catalyze the splicing reaction.

Eukaryotic RNA Processing: Modifications and Splicing

Study Guide - Practice Questions