Encystment. It refers to the formation of an outer protective covering around a spore during unfavourable period.

Endarch. When xylem and phloem are present on the same redius as in stem of seed plants, then the arrangement is referred to as endarch.

Endemic. Confined to a given region, e.g. an island or country. (Of pest or disease – producing parasites), continuously occurring in a particular area.

Endergonic.
(Of a chemical reaction), requiring energy, as in synthesis by green plants of organic compounds from water and carbon dioxide by means of energy absorbed from sunlight.

Encysted . Surrounded by a cyst or shell.

Endocrinology. Study of hormones, their production, nature, and effects.

Endocytosis.
Collective name for pinocytosis (q.v.) and Phagocytosis

Endoderm. (Entoderm, Entoblast, Endoblast, Hypoblast).
Germ – layer of animal embryo, composed, like mesoderm, of cells which have moved from surface of embryo into its interior during gastrulation; developing into greater part of lining of gut with its associated glands, etc. Term is usually applied to the germ –layer while it is still a demarcated region of the embryo, after gastrulation but before differentiation into derived tissues; and all tissues at later stages derived from the embryonic layer may be called endoermal.