Answer:
Point mutation is the mutation that affect the single nucleotide base.
Explanation:
In the present question, ATG is replaced by TTG, that is, A (adenine, purine) is replaced by T (thymine, pyrimidine). ATG codes for methionine and TTG codes for leucine.
(a) The resulting mRNA codon will have leucine instead of methionine. ATG is a initiation codon. Without initiation codon.
(b) The resulting change will affect the amino acid also. As methionine will be replaced by leucine. The correct protein synthesis will not occur without the initiation codon.
This type of mutations are known as transversions, where purine (A) is replaced by pyrimidine (T).
