Define point mutation or gene mutation
Dear Student
Point mutation or Gene mutation is defined as a change in a single nucleotide or a pair of nucleotide in the segment of DNA. It is of following types:-
1- Frame shift mutation- It includes any insertion or deletion of a base pair from a segment of DNA which alters the reading frame of codons. This alters the protein product of that gene.
2- Transition mutation- It involves the replacement of a purine base from another purine base and pyrimidine base from another pyrimidine base. Example- A ⇋G, C⇋T
3- Transversion mutation- In this a pyrimidine base is replaced with a purine base or vice-versa.
Example- A⇋T, C⇋G
4- Base analogue mutation- There are certain chemicals whose molecular structure looks similar like a nitrogenous base of DNA. These chemicals are called as base analogues which replace their similar nitrogenous bases. Thus, they alters the base pairs of DNA. Example- . 5-bromouracil substitutes at the place of Thymine and pairs with Guanine.
Regards
Point mutation or Gene mutation is defined as a change in a single nucleotide or a pair of nucleotide in the segment of DNA. It is of following types:-
1- Frame shift mutation- It includes any insertion or deletion of a base pair from a segment of DNA which alters the reading frame of codons. This alters the protein product of that gene.
2- Transition mutation- It involves the replacement of a purine base from another purine base and pyrimidine base from another pyrimidine base. Example- A ⇋G, C⇋T
3- Transversion mutation- In this a pyrimidine base is replaced with a purine base or vice-versa.
Example- A⇋T, C⇋G
4- Base analogue mutation- There are certain chemicals whose molecular structure looks similar like a nitrogenous base of DNA. These chemicals are called as base analogues which replace their similar nitrogenous bases. Thus, they alters the base pairs of DNA. Example- . 5-bromouracil substitutes at the place of Thymine and pairs with Guanine.
Regards