Viral Diseases and Immunity

This option is correct because human immunodeficiency virus (HIV) is spherical with a diameter of about 90-120 nm. Its genome consists of single-stranded RNA associated with reverse transcriptase enzyme.

AIDS is primarily transmitted through sexual contact, along with other routes like blood transmission and from mother to child during pregnancy/birth. It is NOT transmitted through air (like influenza), water (like cholera), or casual physical contact like touching or hugging. This is a crucial public health fact about HIV/AIDS.

A retrovirus is an RNA virus, which replicates inside a host cell by the process of reverse transcription. Initially it employs its own reverse transcriptase enzyme to produce DNA from its RNA genome. This is the opposite of the normal pattern and hence, it is called retro or backwards. This new DNA is in turn included into the host's genome by an integrase enzyme.

EM or electron microscopy is the process by which the size of a virus can be measured accurately.

env gene codes for a protein called gp160 in HIV capsid that is broken down by a cellular protease to form gp120 and gp41.

HIV is composed of two copies of positive single-stranded RNA that codes for the virus's nine genes enclosed by a conical capsid composed of 2000 copies of the viral protein.

Pyroptosis is a form of programmed cell death associated with antimicrobial responses during inflammation. In this process, abortively infected cells that recognize certain danger signals within themselves produce cytokines, swell, burst and die.

Lys tRNA primer specifically tRNA lys3 is the primer for HIV-1 reverse transcriptase.

Furin protein is one of the proteases responsible for the proteolytic cleavage of HIV envelope polyprotein precursor gp160 to gp120 and gp41 prior to viral assembly.

rev is an essental regulatory arrangement important for the synthesis of major viral proteins and is hence essential for viral replication.

People with Δccr5 mutation are resistant to R5 viruses because these viruses use CCR5 receptors for entry into the cell.

CRF02_AG is a circulating recombinant form of West African and Central European sub-types of HIV.

Viral infectivity factor (vif)'s role is to disrupt the antiviral activity of the human enzyme APOBEC by targeting it for ubiquitination and cellular degradation. APOBEC is a cytidine deaminase enzyme that mutates viral nucleic acids.

If HIV-1 (-) or indeterminate and HIV-2 (-) are there, nucleic acid test must be carried out to detect the acute infection of HIV-1 or its absence.

Untreated HIV patient dies within 9-11 years due to AIDS.