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Virus

An infectious agent often associated with human, plant, and animal diseases.

Obligate intracellular parasites

Viruses that cannot reproduce outside of living cells.

Lytic cycle

A process where viral reproduction occurs and the host cell undergoes lysis to release viral particles.

Lysogenic cycle

A lifecycle where viruses do not immediately reproduce and can integrate into the host's DNA, remaining latent.

Bacteriophage

Viruses that specifically infect bacteria.

Retrovirus

RNA animal viruses that have a DNA stage during their lifecycle.

Prophage

Viral DNA when it integrates into the bacterial DNA in the lysogenic cycle.

Emerging viruses

Viruses that have recently caused widespread diseases in humans, such as AIDS or SARS.

Viroids

Naked strands of RNA that direct cells to produce more viroids.

Prions

Infectious agents composed of protein that cause degenerative diseases.

Capsid

The outer protein coat of a virus that encases its nucleic acids.

Enzyme reverse transcriptase

An enzyme found in retroviruses that converts RNA into complementary DNA (cDNA).

High mutation rates

The rapid change in viruses that allows them to evolve and occasionally jump species.

Host specific

Viruses that can only infect certain species or types of cells.

Viral genome

The genetic material of a virus, which can be either RNA or DNA but not both.