Which of the following scenarios best explains the relationship of consensus sequences in pre-mRNA and the function of the spliceosome?
a)
A mutation near the 3' splice site alters a key part of the consensus sequence. This results in the spliceosome skipping the downstream exon, leading to a truncated protein.
b)
The spliceosome recognizes the polyadenylation (poly-A) signal in the pre-mRNA, enabling accurate removal of introns and joining of exons.
c)
A mutation occurs that disrupts the consensus sequence near the 5' splice site. As a result, the spliceosome cannot assemble on the pre-mRNA, and splicing fails.
d)
The spliceosome binds directly to intronic sequences in the middle of introns, and doesn't need the consensus sequences (which are used for capping and tailing).