EVERYDAY SCIENCE

Detailed explanation-1: -The virus’s genome is uncoated from the protein and injected into the host cell. Then the viral genome hijacks the host cell’s machinery, forcing it to replicate the viral genome and produce viral proteins to make new capsids. Next, the viral particles are assembled into new viruses.

Detailed explanation-2: -During attachment and penetration, the virus attaches itself to a host cell and injects its genetic material into it. During uncoating, replication, and assembly, the viral DNA or RNA incorporates itself into the host cell’s genetic material and induces it to replicate the viral genome.

Detailed explanation-3: -Positive-sense RNA ((+)RNA) viruses enter animal cells by endocytosis and plant cells through wounds. When the virus is inside the cell, the (+)RNA genome is released into the cytosol, where it is translated by the host ribosomes.

Detailed explanation-4: -Cell surface receptors. Different viruses use specific cell surface receptors for attachment. HIV-1 requires CD4 as a receptor and chemokine receptors CCR5 or CXCR4 as coreceptors. Influenza viruses bind to terminal sialic acid residues found on cell surface glycoproteins.

Detailed explanation-5: -After a retrovirus enters a host cell, reverse transcriptase converts the retroviral RNA genome into double-stranded DNA. This viral DNA then migrates to the nucleus and becomes integrated into the host genome. Viral genes are transcribed and translated.