Question

why is reverse transcriptase essential for a retrovirus to successfully infect a host? it is responsible for integrating the viral genome into the host genome. it creates a complementary cdna copy of host genes to block their translation. it creates a complementary cdna copy of the viral rna genome. it is responsible for the evasion of host defense mechanisms. it creates the mrna necessary for expression of viral genes.

Explanation:

Reverse - transcriptase is an enzyme that synthesizes a complementary DNA (cDNA) copy from a viral RNA genome. This is essential for retroviruses as their genetic material is RNA, and to integrate into the host genome (which is DNA - based) and replicate, they need to convert their RNA into DNA.

Answer:

It creates a complementary cDNA copy of the viral RNA genome.