Based on the information provided in the figure below, choose whether introns or
ID: 259611 • Letter: B
Question
Based on the information provided in the figure below, choose whether introns or 3' untranslated regions (UTR) of a gene have higher rates of nucleotide substitution and the reason why.
Introns have higher rates of substitutions since the introns do not code for protein. The 3' UTR of a gene may have a functional role in regulating mRNA stability and translation 3 Pseudogene 0 Synonymous__ Introns have higher rates of substitutions because the introns do not code for protein The 3' UTR may be translated, so there is a functional constraint on substitutions Nonsynonymous The 3' UTR of a gene has a higher rate of nucleotide substitution since they mutate rapidly through the process of exon shuffling O Both should have approximately the same substitution rates since both introns and the 3' UTR are noncoding regions of the gene 6 9 6 9 5 untranslated 3 untranslated 9 5 untranslated 3 untranslated region Exons region 9 9Explanation / Answer
Ans 1. Introns have higher rates of substitutions since the introns do not code for protein, The 3' UTR of a gene may have a functional role in regulating mRNA stability and translation.
Reason. Introns are non-coding region of mRNA which are ventually spliced so they can any have kind change in genetic alteration which will not affect the translation of a polypeptide.
But 3' UTR has the following function:
a) They have binding site for regulatory proteins, miRNA etc which regulates the translation process.
b) It has a silencer region for binding of repressor protein that inhibits translation of that certain mRNA
c) They contain poly A tail at the end of mRNA which binds Poly A binding proteins and help in stability of the mRNA and regulation of translation.
For the above reasons if their are neucleotide substitution cell function might be hampered.