5. Gene Regulation

Posttranscriptional Control — Quiz

Test your understanding of posttranscriptional control with 5 practice questions.

Practice Questions

Question 1

How does alternative polyadenylation leading to a shorter 3′ UTR typically affect mRNA regulation?

Question 2

An mRNA isoform A contains three miRNA target sites in its 3′ UTR, whereas isoform B contains only one due to alternative polyadenylation. Which isoform is expected to have higher translation efficiency and why?

Question 3

A point mutation in the polypyrimidine tract upstream of a 3′ splice site reduces binding of U2AF65. Which splicing outcome is most likely?

Question 4

Which component deposited near exon–exon junctions during splicing marks mRNA for nonsense-mediated decay if a premature stop codon is present upstream?

Question 5

Given a pre-mRNA with constitutive exons 1 and 4, and two cassette exons 2 and 3 that can be independently included or skipped, how many unique mature mRNA isoforms are possible?