Question

CRISPR is considered an example of specific immunity in bacteria and archaea because it____________.

A. prevents archaeal DNA from infecting bacteria.

B. destroys host DNA.

C. prevents the production of cell surface receptors that allow phages to get into the cell.

D. minimizes damage from foreign DNA by using guide RNA similar to the invader and cas proteins to cleave the foreign DNA.

E. methylates host DNA and destroys invading DNA.

Answer 1

Ans) D. minimizes damage from foreign DNA by using guide RNA similar to the invader and cas proteins to cleave the foreign DNA.

Explaination:CRISPER CAS9 System provides  a special adaptive immunity where bacteria form crisper array by capturing snippets of invading virus and integrate them into their interspacer segment. These crisper array work as memory and when similar virus or closely related virus attack the bacteria they form a short segment of RNA that is guide RNA using these CRISPER to target the invading virus.These g RNA binds to foreign target DNA and cas9 enzyme cut the targeted DNA.