NEET BIOLOGY

Detailed explanation-1: -This process of changing and selection of successful variants is called “virus evolution.” Some mutations can lead to changes in a virus’s characteristics, such as altered transmission (for example, it may spread more easily) or severity (for example, it may cause more severe disease).

Detailed explanation-2: -Mutations involve changes to the sequence of an organism’s genetic code. As you have learned, viruses typically mutate more rapidly than human cells do. This is because human cells have mechanisms to proofread the genome and also mechanisms to repair a sequence if an error is detected.

Detailed explanation-3: -Spontaneous mutations can occur because of replication errors or as a consequence of lesions introduced into DNA during normal cell growth. Induced mutations arise after treatment of the organism with an exogenous mutagen being physical or chemical agent increasing the frequency of mutations.

Detailed explanation-4: -When a change means the virus gets into a cell, it can start replicating a new version of itself. This mutation is called is a new strain or variant. It is a normal process that happens with all viruses. For more information on new COVID-19 variants, see COVID-19 variants.