Question

2. As an undergraduate student in a university laboratory, you are challenged with the problem of determining whether the mRNA that you have been given is from a eukaryotic cell or prokaryotic cell. Indicate TWO features in the sequence you will look for to determine whether the mRNA is eukaryotic or prokaryotic. (2 marks)

Answer 1

To determine if the mRNA is eukaryotic or prokaryotic, check for the presence of introns and exons as well as 5' cap and poly-A tail modifications, which are indicative of eukaryotic mRNA.

Step-by-step explanation:

Distinguishing Features of Eukaryotic and Prokaryotic mRNA

To determine if an mRNA is from a eukaryotic or prokaryotic cell, you can look for two distinct features in the mRNA sequence:

• The presence of introns and exons. Eukaryotic genes are typically interrupted by non-coding sequences called introns, which are spliced out during RNA processing to produce the mature mRNA. Thus, eukaryotic mRNA will generally only have exons, which are the coding sequences that remain in the mRNA to be translated into protein.
• A 5' cap and a poly-A tail. These modifications are found on eukaryotic mRNAs and are part of the processing that occurs before the mRNA is transported out of the nucleus. The 5' cap is a modified guanine nucleotide added to the beginning of the mRNA, and the poly-A tail is a string of adenine nucleotides added to the end. Prokaryotic mRNA lacks these features because they do not undergo the same processing and do not have a nucleus.

By examining these factors in your mRNA sequence, you can distinguish whether it came from a eukaryotic or prokaryotic cell.