2 Answers

Jeanhee · Answer 1 · 2024-08-30T09:12:40+0000

Final answer:

All of the statements about the splicing of pre-mRNA via a spliceosome are true except for d. Alternative splicing can lead to the synthesis of several forms of ribosomes from a set of genes.

Step-by-step explanation:

All of the statements about the splicing of pre-mRNA via a spliceosome are true except for d. Alternative splicing can lead to the synthesis of several forms of ribosomes from a set of genes. Alternative splicing can lead to the synthesis of several forms of proteins from a set of genes, not ribosomes. The splicing of pre-mRNA occurs in the nucleus and is carried out by complexes of proteins and RNA molecules called spliceosomes. Introns are removed and degraded, while exons are rejoined to produce mature mRNA that can be translated into proteins.

Diego Osornio · Answer 2 · 2024-09-04T17:45:46+0000

Final answer:

The statement about the splicing of pre-mRNA via a spliceosome that is false is that U1 snRNP binds to the 3' splice site (Option E).

Step-by-step explanation:

The incorrect statement regarding pre-mRNA splicing is that U1 snRNP binds to the 3' splice site, while it actually binds to the 5' splice site. The correct sequence of events during the splicing process is that U1 snRNP binds to the 5' splice site of the pre-mRNA. U2 snRNP does bind to the branch site, and a trimer consisting of U4/U6 and U5 snRNP does indeed bring the exons closer together.

Furthermore, the intron is released in the form of a lariat after the 5' splice site is cut first, followed by the 3' splice site being cut. Therefore, the incorrect statement is that U1 snRNP binds to the 3' splice site when, in fact, it binds to the 5' splice site.