Viruses

Plant cell walls hinder entry, making wounds important portals.

Phages mediate transduction, transferring genes between bacteria.

HIV infects CD4+ T helper lymphocytes leading to immune deficiency.

Viral attachment proteins must recognize host cell receptors.

Viral components are assembled into mature infectious particles.

Naked viruses contain only nucleic acid and capsid without an envelope.

Frequent mutations enable influenza viruses to evade immune responses.

HPV infects epithelial cells and may lead to warts and certain cancers.

The capsid safeguards viral nucleic acid against environmental damage.

Most bacteriophages inject nucleic acid while the capsid remains outside.

DNA or RNA nature is a fundamental basis for viral classification.

Animal viruses commonly enter through receptor-mediated endocytosis or membrane fusion.

Rabies virus shows strong neurotropism and damages nervous tissue.

Latency involves persistence of viral genome with minimal viral production.

TMV capsid proteins are arranged helically around RNA.

Integrated viral DNA is called a prophage.

Viruses are acellular, whereas living cells possess cellular structure.

Tail fibers recognize and bind specific bacterial receptors.

Hepatitis B virus is a DNA virus and an important human pathogen.