HIV, the virus that causes AIDS, is a retrovirus. Which of the following sentences BEST defines a retrovirus? A. A retrovirus converts DNA into RNA,

B. A retrovirus causes lifelong infection.

c. A retrovirus is an old virus that infects new cells.

D. A retrovirus inserts DNA into the host cell's genes.

The answer is D a retrovirus inserts DNA into the host cells genes

the correct answer is option b

behavioral response need communication and thus co-ordination at several levels such as interaction among cells, organ system and the entire organism.

behavioral response produces both internal and environmental stimulus.