Read HIV by Target, Genome and Transmission
Read HIV questions through four anchors: its RNA genome, its target cells, routes of transmission and the immune decline that permits opportunistic infection.
Living-system questions are solved by matching a structure or organism to its function, process and stated condition.
Genome and target cells
HIV is a retrovirus with two copies of single-stranded RNA. Its envelope protein gp₁₂₀ binds CD₄ and co-receptors on helper T cells and macrophages, enabling entry. Progressive loss of helper T cells weakens acquired immune coordination.
Understand the consequences
As immune defence falls, opportunistic infections can be viral, bacterial, fungal or protozoan. AIDS describes the advanced syndrome associated with this severe immune deficiency.
Sort transmission from casual contact
HIV can spread through infected blood, shared contaminated needles, sexual exposure and mother-to-child transmission. Sharing meals or ordinary social contact does not transmit HIV.
OlympIQ exam lens
- ✓HIV genome: two copies of ssRNA, not DNA.
- ✓CD₄-bearing cells include helper T cells and macrophages.
- ✓AIDS is associated with declining helper T-cell function and opportunistic infections.
- ✓Shared meals do not transmit HIV.
Do not confuse a retrovirus's RNA genome with the DNA intermediate it makes inside an infected cell.
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