Question

Mutations are an occurrence that can take place. Sometimes those effects can be very damaging to the cell and host. Please choose two types of mutations and provide a valid argument on why these two mutations can be a major issue for the organism. Make sure to define the mutations.

Answer 1

Two types of mutations :-

1. Point Mutations:-

Point mutation are alteration in a single nucleotide or small deletion which affects the function of a single gene. These mutations can be of many types:-

a) Missense mutation- A single nucleotide change leads to change in a single amino acid.

b) Nonsense mutaion- A single nucleotide change in the open reading frame leads to formation of stop codon, as a result the translation of the mRNA is prematurely terminated.

c) Frameshift by addition- It occurs due to incorporation of a single nucleotide in the open reading frame, which completely changes the sequence of the protein due to shift of the wild type frame.

d) Frameshift by deletion- It occurs due to deletion of a single nucleotide in the open reading frame, which completely changes the sequence of the protein due to shift of the wild type frame.

Point mutations can cause various genetic disorder in the host progeny, one of the notable mutation is sickle cell anemia. All of the above mutations leads to changes in the wild type DNA sequence and thus affect the protein. Sometimes the important proteins are not expressed at all, or are truncated and non functional. A single amino acid change can be very deleterious for the host, as it can change protein structure.

2. Chromosomal Mutations

Chromosomal Mutations involves alteration in large segement of any chromosome due to double stranded breaks. It can occur by inversion, deletion, translocation and insertion of chromosomal fragment, these alteration can cause various abnormalities in the host. One of serious problems it can cause is activation of proto oncogenes and supression of tumer suprresion genes.