Invasion and replication in cells.

Plant disease causing patterned discoloration.

Contagious respiratory virus causing flu.

Virus causing acquired immune deficiency syndrome.

Infections caused by viral agents.

Cancer-causing virus in connective tissues.

Contagious virus causing rash, fever.

Virus causing lifelong recurrent infections.

Copying genetic material to multiply.

Deadly virus causing neurological disease.

Human immunodeficiency virus causes AIDS.