MDCAT 2026 MCQs

Retroviruses possess an RNA genome and use reverse transcriptase.
HIV is an important human retrovirus.

Enveloped viruses possess a lipid membrane acquired from host cells.
Non-enveloped viruses lack this outer lipid layer.

Enveloped viruses possess a lipid membrane acquired from host cells.
Non-enveloped viruses lack this outer lipid layer.

Enveloped viruses possess a lipid membrane acquired from host cells.
Non-enveloped viruses lack this outer lipid layer.

HIV binds mainly to CD4 receptors on helper T cells.
Progressive loss of these cells weakens adaptive immunity.

HIV binds mainly to CD4 receptors on helper T cells.
Progressive loss of these cells weakens adaptive immunity.

HIV binds mainly to CD4 receptors on helper T cells.
Progressive loss of these cells weakens adaptive immunity.

HIV can spread through infected blood, sexual contact and from mother to child.
Ordinary social contact and mosquitoes do not transmit it.

HIV can spread through infected blood, sexual contact and from mother to child.
Ordinary social contact and mosquitoes do not transmit it.

HIV can spread through infected blood, sexual contact and from mother to child.
Ordinary social contact and mosquitoes do not transmit it.

AIDS is the advanced stage of HIV infection.
Severe immune suppression permits opportunistic infections and cancers.

Analogous structures often arise through convergent evolution.
Bird and insect wings are examples.