How would each of the following types of mutation affect the function of the protein that is expressed from a gene:
a) Nonsense
b) Missense
EXPERT ANSWER
Answer
A). Nonsense mutations: This mutation is caused by point mutations. If the codon in mRNA is converted to nonsense codons, it causes the polypeptide chain termination. So the pre-termination of polypeptide chain causes deliterious effects in the organism.
B). Missense mutations: A codon change in mRNA squence causes change in the amino acid sequence in the polypeptide chain. This is called as missense mutation. Due to change in amino acid sequence in the polypeptide chain, the properties of polypeptide chain will. be altered.