Read the following statements that describe an hiv infection. what is the correct order in which they occur?

1) reverse transcriptase uses viral rna as a template to make viral dna.
2) virus coat fuses with cell membrane and viral rna enters the cell.
3) virus attaches to host cell membrane.
4) the new viruses bud off from the host cell membrane.
5) viral dna enters nucleus and inserts itself into host dna.
6) viral mrna directs the host cell to assemble viral proteins.

choices:

a. 2,3,6,1,5,4

b. 2,3,1,5,6,4

c. 3,2,1,6,5,4

d. 3,2,1,5,6,4

The correct answer is -

D. 3,2,1,5,6,4

Explanation:

Infection of HIV (human immuno deficiency virus) into the host cell primarily involves the following steps-

1) Binding of virus to host cell,

2) Fusion of viral coat to host cell membrane so that entry of virus takes place.

3) Action of reverse transcriptase enzyme to make viral DNA from viral RNA,

4) Integration of viral DNA into host genome,

5) Replication of viral genome along with host genome.

6) Assembly of viral particles through viral mRNA (formed through transcription).

7) Budding of new viral particles from the membrane.

According to this sequence, option D) is the right answer.

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.