Suppose that a scientist deletes the AAUAAA consensus sequence, the poly(A) tail, or the 5' cap from pre‑mRNAs in an mRNA. She then observes the effects on RNA regulation. Assign each RNA regulation consequence to the type of deletion most likely to result in the consequence.

1. AAUAAA deletion
2. Poly(A)‑tail deletion
3. 5' cap delatation

A. Introns are not removed from pre m-RNA
B. The pre-mRNA is not cleaved at the cleavage site
C. The mRNA is not transported to the cytoplasma

Explanation:

(A) introns are not removed from the pre-mRNA due to 5' deletion;

(B) the pre-mRNA is not cleaved at the cleavage site due to AAUAA deletion

(C) the mRNA is not transported to the cytoplasm due to poly A tail deletion;

AAUAA deletion:  if we delete the AAUAA  sequence then there is the change of sequence of pre- mRNA that the pre-mRNA is not cleaved at the cleavage site .

Poly(A) tail deletion: Poly(A) tail is the long tail of Adenine in the 3' end of mRNA, after the deletion of Poly(A) tail, it affects the transport of mRNA from the nucleus to the cytoplasm and  the mRNA is not transported to the cytoplasm if tail is deleted.

5' cap deletion; the effect of 5' cap deletion is that introns are not removed from the pre-mRNA. The process of intron removing and exon joining is called RNA splicing.

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."