Question

What is mutation? Explain in detail

Answer 1

The word “mutation” was originally derived from the Latin word “mutare” means “to change.” In biology, mutation refers to changes in chromosomes and genes, which typically manifest physically. Mutation occurs when a DNA gene is damaged or transformed in such a way as to alter the genetic message carried by that gene.

Complete step by step answer:
Due to the error in replication, mutagen exposure and changes that happen due to viral infections or alterations occurred in a DNA sequence which results in genetic abnormalities, is known as mutation.
The agents that cause mutations are called mutagens. For example, UV rays, microorganism, and certain chemicals.
Types of mutation
-Gene mutation-A permanent alteration in the DNA sequence that changes the function of it is called as a gene mutation
-Point mutation– A change in the single base of the DNA sequence( Single nucleotide polymorphism)
-Insertion– An addition of a base into the gene sequence of the DNA (addition mutation)
-Deletion– Occurs when bases are deleted from the gene sequence.
-Inversion– Occurs when gene sequences inverted and then inserted back into the original sequence.
-Substitution– Occurs when bases of a gene sequence are replaced by other bases.
-Duplication– Occurs when bases are duplicated in a gene sequence
-Copying error-Occurs during cell division while replication.
-Frameshift mutation- Alteration in the base pair causes abnormal reading of frames which results in the formation of an abnormal protein.
-Silent mutation - It is non-expressive. In silent mutation, a new codon codes for the same amino acid as the wild-type one
-Chromosome mutation- A change or alteration into the structure or number of chromosomes.
-Aneuploidy – Change in the number of the chromosome which results in a genetic abnormality

Note: The term “mutation” was coined by Hugo De Vries in 1890.
After the findings of Hugo de Vries, the mechanism of mutation was studied by Morgan in 1910.
In 1927, H. J. Muller performed experiments of artificial mutagenesis using the X-rays. He had introduced mutation in Drosophila. For that, he was awarded the Nobel prize in 1946.