Question

Describe the different types of DNA mutations: a. point mutation b. base substitution c. frameshift d. triplet repeat

Answer 1

Answer:

In point mutation, alteration affects only one single nucleotide.

In base substitution mutation, one single nucleotide is swapped with another nucleotide

In frameshift mutation, the addition or deletion of one or more base pairs could lead to shift in the arrangement

In triplet repeat mutation, a base pair repeats until it reaches threshold limit

Explanation:

In point mutation, alteration affects only one single nucleotide. This alteration could be insertion, deletion or substitution of only one single nucleotide.  

In base substitution mutation, one single nucleotide is swapped with another nucleotide during the replication process of DNA.  

In frameshift mutation, the addition or deletion of one or more base pairs could lead to shift in the arrangement of triple nucleotide bases.  

For instance if the base pair is

AAT  GCC  CGA TCT

If insertion occurs at second base pair, then the frame will shift as below

AAT  GAC  CCG ATC  T….

In triplet repeat mutation, a base pair repeats until it reaches threshold limit and then becomes unstable