Question

Distinguish between gene mutations and chromosomal mutations. In your own words, describe the following three types of gene mutations: insertion, deletion, and base substitution. Give a specific example of each type and describe in detail how the DNA is altered in each case. What are the phenotypic ramifications of each of these small gene mutations?

Answer 1

Answer :-

Distinguish between gene mutations and chromosomal mutations :-

Gene mutation is described as the change in the nucleotide sequence, in a particular gene, whereas chromosomal mutation is a change in several genes, in the chromosome.

(1) -Insertions are mutations in which extra base pairs are inserted into a new place in the DNA. The number of base pairs inserted can range from one to thousands. For example :- Huntington's disease.

(2)- Deletions are mutations in which a section of DNA is lost, or deleted. The number of base pairs deleted can again range from one to thousands. For example :- Deletion syndrome.

(3) - Substitution is a mutation in which there is an exchange between two bases. For example :- Sickle cell anaemia.