virus
- Viruses are a unique group of biological entities known to infect every type of cell, including bacteria, algae, fungi, protozoa, plants, and animals
- All viruses contain a nucleic acid genome (RNA or DNA) and a protective protein coat (called the capsid). The nucleic acid genome plus the protective protein coat is called the nucleocapsid which may have icosahedral, helical or complex symmetry. Viruses may or may not have an envelope. Enveloped viruses obtain their envelope by budding through a host cell membrane.
- The study of viruses is known as virology, a sub-specialty of microbiology.
- Viruses also carry out natural "genetic engineering": a virus may incorporate some genetic material from its host as it is replicating, and transfer this genetic information to a new host, even to a host unrelated to the previous host. This is known as Transduction
Properties of virus
Obligate intracellular parasites of bacteria, protozoa, fungi, algae, plants, and animals.
Ultramicroscopic size, ranging from 20 nm up to 450 nm (diameter).
Do not independently fulfill the characteristics of life
Basic structure consists of protein shell (capsid) surrounding nucleic acid core.
Nucleic acid can be either DNA or RNA but not both.
Nucleic acid can be double-stranded DNA, single-stranded DNA, single-stranded RNA, or double-stranded RNA.
Ultramicroscopic size, ranging from 20 nm up to 450 nm (diameter).
Do not independently fulfill the characteristics of life
Basic structure consists of protein shell (capsid) surrounding nucleic acid core.
Nucleic acid can be either DNA or RNA but not both.
Nucleic acid can be double-stranded DNA, single-stranded DNA, single-stranded RNA, or double-stranded RNA.
Medical Importance of Virus
Viruses, the small infectious agents that are responsible for many human diseases, can be used treat various diseases (virotherapy), an application that has promising potential in the fields of cancer treatment and gene therapy.
Viruses can also be used to produce vaccine antigens and antibodies, which have important pharmaceutical uses.
To isolate and identify viruses in clinical specimen to research in detail the viral structures, multiplication cycles, genetics, and effects on the host cells