germ theory

germ theory

n.

The doctrine holding that infectious diseases are caused by the activity of microorganisms within the body.

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germ theory

Etymology: L, germen, sprout; Gk, theoria, speculation

the concept that all infectious and contagious diseases are caused by living microorganisms. The science of bacteriology developed after establishment of this theory. Also called pathogenic theory of medicine.

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germ

1. old-fashioned and lay term for a pathogenic microorganism.

2. living substance capable of developing into an organ, part or organism as a whole; a primordium. Commonly used to refer to the embryos of wheat grains which are removed during milling and sold separately as wheat germ.

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germ cell

direct descendants of the primordial cells which originate from the yolk sac endoderm and migrate to the gonadal ridges of the embryo, where they give rise to either ova or spermatozoa. Called also gonocytes, sex cells.

germ cell tumor

a rare tumor in dogs, similar to more common lesions in humans. Similar to pituitary adenomas in distribution and cellular characteristics.

germ line

the genetic material as it is transferred via the gametes, before being modified by somatic recombination or mutation.

germ line cells

gametes.

germ line transmission

a mode of transmission, particularly of retroviruses, whereby the genome of the virus is integrated into the chromosomal DNA and transmitted via gametes to offspring.

germ plasma evaluation program

a planned investigative, large scale breeding program aimed at accumulating comparative information on the relative performance of various breeds and crossbreeds of agricultural animals.

germ theory

1. all organisms are developed from a cell.

2. infectious diseases are of microbial origin.

germ tube

a tube-like structure that develops during the growth of some fungi and becomes a hypha; a feature of the yeast, Candida albicans.

wheat germ

see wheat germ.