Most viruses have single-stranded DNA or RNA as their genetic code. The double-stranded DNA usually doesn’t have a tail, making it much less difficult to recognize. The study of living plant viruses led some of the first great experiments in molecular biology. Because they have life cycles that involve replicating themselves, viruses are a great tool to study the molecular processes and life forms that we see around us.


A virus is a self-replicating process. The virus is passed from one host cell to another by contact with an infected object or its membranes. The particles that make up the virus attach to the surface of the uninfected host cell and then reproduce. This is called the viral envelope. In some cases, a sequence of instructions specific to the type of virus or strain is written onto these envelopes. These genetic instructions regulate the various steps in the lytic cycle, which is a process by which proteins break down a glycol molecule to release the nutrients that nourish the plant.

Every virus needs a complementary template to copy itself. Some viruses use a protein called a caps RNA, or caps to provide their amino acids. Other viruses use an RNA called a primer. The caps RNA and primer are put together in a reaction chamber, which caters to the viral enzyme’s instructions for duplication.

The caps and primer RNA are put into a growth plate where they are kept for about 24 hours. Then the virus’ genetic makeup can be studied. Each strain of a virus has a unique set of caps and primer RNAs. All strains of a virus have a genome, or genetic code. Genomes are collections of genes that are the exact same coding sequence for all strains, but differ in the base pairings that make up the transcription DNA.

When a virus replicates its genetic material contained within its genome, the viral particles bombard their target cells with viral antigens. Antigens are cellular triggers that cause cellular immunity. The virus’ genetic code is then translated into amino acids by ribosomes, making copies of itself in bacterial colonies. These bacteria then multiply to form chains of viral particles.

Viruses need not be living to replicate themselves. They can be created using laboratory equipment. Any type of virus that can infect a host cell can replicate. However, some viruses cannot reproduce on host cells because their machinery is insufficient for their replication requirements.