Question

This diagram depicts the HIV life cycle. Identify the main stages of the cycle by placing the captions in the correct location the diagram. You will not use all of the captions. 

Answer 1

The seven stages of the HIV life cycle are:

1. binding 5. replication

2. fusion 6. assembly

3. reverse transcription 7. budding

4. integration

Binding: HIV binds to receptors on the surface of a CD4 cell

Fusion: The HIV envelope and the CD4 cell membrane join together,which allows HIV to enter the CD4 cell.

Reverse transcription: Inside CD4 cell, HIV releases and uses reverse transcription to convert its genetic material HIV RNA-into HIV DNA. This conversion allows HIV to enter the CD4 cell nucleus and combine with cell's DNA.

Integration: Inside the cell, HIV releases integrase to insert its viral DNA in to the DNA of the cell.

Replication: Once integrated into cell DNA, HIV begins to use the machinery of the cell to make long chains of HIV proteins. The protein chains are building blocks of more HIV.

Assembly: New HIV proteins and HIV RNA move to surface of the cell and assemble into immature HIV.

Budding: Newly formed immature HIV pushes itself out of host cell. The new HIV releases protease. Protease breaks up the long protein chains in the immature virus,creating the mature virus.

From the cycle,the 4 main stages in HIV cycle given in question are:

1.HIV binds to the receptor on the host cell and inserts HIV DNA in to the host cell.

2.HIV reverse transcriptase produces viral DNA, which is inserted in to the host cell DNA

3.New HIV RNA and proteins are produced, and protease cuts the proteins into correct lengths

4.New viruses containing HIV RNA and proteins bud off the host cell