Answer:
Extra nucleotides. Extra nucleotides
Step-by-step explanation:
When the transcription of a gene ends, a poly(A) tail is added at the end 3' of the pre messenger RNA (mRNA) The poly(A) tail is a long sequence of several hundred adenine nucleotides. The polyadenylation is part of the the maturation process of the mRNA for translation. The poly(A) tail is important for stability of mRNA; eventually it is shortened and, when it is short enough, is enzymatically degraded.