Question

what is true regarding antigentic drift and antigentic shift together?

a. polymerase makes errors in synthesis

b. shuffling different fragments of genome occurs

c. the process can lead to new variations immune systems wont recognize

d. the process leads to new variations that the immune system will recognize

Answer 1

Option C- the process can lead to new variations immune systems wont recognize .

Antigenic Shift:it is a sudden and drastic change occuring in virus(Example :Influenza virus)in which either 2 or more different strains of a virus Combines or 2 or more different viruses combine to form a new subtype of Virus .

So the new subtype of the virus formed have mixture of the surface antigens which was present in original viral types that combines.So that the surface antigen in new virus is so different from the subtype in humans.Hence human immune system usually donot recognise the new virus

Antigenic Drift:This is a slow Change occuring in virus(Example Influenza virus) due to accumulation of mutations in the virus genes that code for surface proteins in the virus.Here even though the new Virus is Genetically similar to the original virus (not a new subtype),since there is mutation in the surface proteins,Human immune system usually fails to recognise these viruses.

So the Antigenic shift & Antigenic Drift causes Pandemics,Epidemics etc