Viruses

Capsomeres are repeating protein units that assemble into the viral capsid.

Plant viruses often enter through injuries and are spread by insect vectors.

Poxviruses possess a complex brick-shaped structure unlike simple helical or icosahedral forms.

RNA polymerases lack proofreading ability, leading to frequent mutations.

T4 bacteriophage possesses an icosahedral head and tail apparatus.

Adsorption is the initial binding of a virus to specific host receptors.

Retroviruses carry RNA and use reverse transcriptase to synthesize DNA.

Reverse transcriptase converts viral RNA into DNA inside the host cell.

Icosahedral symmetry provides stability and efficient genome packaging.

Lipid envelopes are disrupted by detergents, reducing infectivity.

Dengue virus belongs to the Flavivirus group and contains RNA.

Newly produced phages rupture the bacterial cell releasing progeny viruses.

Capsid is the protein coat that surrounds viral nucleic acid and is present in all viruses. Ribosomes, cytoplasm, and true cellular membranes are absent in all viruses.

Viruses lack cellular organization and consist mainly of nucleic acid enclosed by a protein coat, making them acellular infectious particles.

Viruses can reproduce only inside living host cells because they lack independent metabolic machinery.

A virus contains either DNA or RNA as genetic material but never both simultaneously.

Capsid protects the viral genome and helps in host recognition. Envelope is an additional structure found only in some viruses.

Bacteriophages are viruses specialized to infect bacterial cells.

TMV is a classic plant virus containing single-stranded RNA enclosed in a helical capsid.