Question

Describe the role of reverse transcriptase in HIV replication cycle. Describe all of its roles and the components involved in carrying out its function.

Describe antigenic shift in Flu virus and describe where and how it occurs,

Answer 1

Role of Reverse transcriptase in HIV replication cycle..

• HIV is the most well known example of retroviruses.
• When HIV infects a cell(CD4), it brings with it a genome made of RNA, not DNA.
• The RNA enters the cell, and the reverse transcriptase copies the viral RNA back to DNA. This is known as reverse transcription(Teminism).
• The viral DNA is cut and paste into the host cell DNA. The host cell gets tricked into making lots of proteins for the virus.
• It doesn't notice the instructions have changed and keeps making lots of new viruses
• Although this is bad for the host, it is great for the virus, since the goal of a virus is to survive and make more viruses.

Antigenic shift in flu viruses..

• Antigenic shift is a more major change in the flu virus.
• This shift occurs typically when a human flu virus crosses with a flu virus that usually affects animals (such as birds or pigs).
• When viruses mutate, they shift to create a new subtype that is different from any seen in humans before.