Glossary is usually defined as an alphabetical list of technical terms in some specialized field of knowledge. This knowledge base glossary provides a collection of knowledge base documents that define many technical terms. These terms are arranged alphabetically, but you can quickly jump to a specific term by selecting its first letter from the index of the knowledge base glossary below.

Reproduction or duplication, as of an exact copy of a strand of DNA.

An animal virus (e.g., HIV) that contains the enzyme reverse transcriptase. This enzyme converts the viral RNA into DNA which can combine with the DNA of the host cell and produce more viral particles.

A molecule similar to DNA that functions primarily to decode the instructions for protein synthesis that are carried by genes. See also Messenger RNA; Transfer RNA.

Any of a group of double-stranded RNA viruses having a wheel-like appearance and responsible for acute infantile gastroenteritis and for diarrhea in mice, calves and pigs.

The change of a seronegative test from negative to positive, indicating the development of antibodies in response to immunization or infection.

Showing negative results on a serological examination; showing a lack of antibody.

Cells other than sex or germ cells.

One of the human body`s master cells, with the ability to grow into any one of the body`s more than 200 cell types. All stem cells are unspecialized (undifferentiated) cells that are characteristically of the same family type (lineage). They retain the ability to divide throughout life and give rise to cells that can become highly specialized and take the place of cells that die or are lost. Stem cells contribute to the body`s ability to renew and repair its tissues. Unlike mature cells, which are permanently committed to their fate, stem cells can both renew themselves as well as create new cells of whatever tissue they belong to (and other tissues).

White blood cells that are produced in the bone marrow but mature in the thymus. They are important in the body`s defenses against certain bacteria and fungi, help B lymphocytes make antibodies, and help in the recognition and rejection of foreign tissues. T lymphocytes may also be important in the body`s defense against cancers.

In vitro growth in nutrient medium of cells isolated from tissue.