germe

Germe is a term used in biology and medicine to refer to the starting point of growth, a seed, or a microorganism. In English, the word germ most often denotes a microorganism such as bacteria, viruses, fungi, or protozoa. These organisms can be harmless, beneficial (for example, gut microbiota), or pathogenic, causing disease under certain conditions. The word derives from Latin germen meaning bud or sprout and entered English via Old French.

Germ theory, developed in the 19th century by scientists including Louis Pasteur and Robert Koch, posits that many diseases are caused by microscopic organisms. This insight led to public health measures such as sterilization, aseptic technique, vaccination, and improved sanitation.

In botany, germ also means the embryo inside a seed—the plant’s developmental starter. The process of germination begins when a seed resumes growth after dormancy, typically in the presence of water, suitable temperature, and oxygen.

In genetics the term appears in phrases such as germline, referring to reproductive cells whose genetic material can be passed to offspring, in contrast to somatic cells. The related concept of germ plasm describes hereditary material inherited through the germline.

The term may appear in various languages with similar meanings, particularly in French where germe can denote a germ or a seed, depending on context. In everyday usage, germ commonly signals a microbe or the origin point of growth, depending on context.