NEET BIOLOGY

Detailed explanation-1: -A point mutation occurs in a genome when a single base pair is added, deleted or changed. While most point mutations are benign, they can also have various functional consequences, including changes in gene expression or alterations in encoded proteins.

Detailed explanation-2: -With base substitution mutations, only a single nucleotide within a gene sequence is changed, so only one codon is affected (Figure 1).

Detailed explanation-3: -Single base substitutions are called point mutations, recall the point mutation Glu—–> Val which causes sickle-cell disease.

Detailed explanation-4: -Mutations that involve changes in one or a few nucleotides are known as point mutations because they occur at a single point in the DNA sequence. They generally occur during replication. If a gene in one cell is altered, the alteration can be passed on to every cell that develops from the original one.

Detailed explanation-5: -A point mutation is a genetic mutation where a single nucleotide base is changed, inserted or deleted from a DNA or RNA sequence of an organism’s genome. Point mutations have a variety of effects on the downstream protein product-consequences that are moderately predictable based upon the specifics of the mutation.