Question

What is the function of the AAUAAA sequence near the 3' end of an RNA molecule in eukaryotes?

A) Start codon for translation
B) Polyadenylation signal
C) Shine-Dalgarno sequence
D) Splice site recognition

Answer 1

The function of the AAUAAA sequence near the 3' end of an RNA molecule in eukaryotes is polyadenylation signal. This sequence is recognized by the poly-A polymerase enzyme, which adds a string of approximately 200 A residues, called the poly-A tail, to the pre-mRNA. The poly-A tail plays an important role in protecting the mRNA from degradation and in facilitating the export of the processed mRNA to the cytoplasm for translation.

Step-by-step explanation:

The function of the AAUAAA sequence near the 3' end of an RNA molecule in eukaryotes is polyadenylation signal. This sequence is recognized by the poly-A polymerase enzyme, which adds a string of approximately 200 A residues, called the poly-A tail, to the pre-mRNA. The poly-A tail plays an important role in protecting the mRNA from degradation and in facilitating the export of the processed mRNA to the cytoplasm for translation.

Answer 2

The AAUAAA sequence is a polyadenylation signal in eukaryotic pre-mRNA processing, leading to the addition of the 3' Poly-A Tail vital for mRNA stability, export, and translation efficiency.

Therefore, the correct answer is B,

Step-by-step explanation:

The AAUAAA sequence near the 3' end of an RNA molecule in eukaryotes functions as a polyadenylation signal, which is essential in the processing of pre-mRNA into mature mRNA. This signal sequence is recognized by enzymes that cleave the pre-mRNA. Following this cleavage, an enzyme called poly-A polymerase adds a string of adenine nucleotides, forming the 3' Poly-A Tail. This tail is important for protecting the mRNA from degradation and also plays a role in the export of the mRNA from the nucleus to the cytoplasm, and in translation efficiency. Therefore, the correct answer is B) Polyadenylation signal.