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isoleucine

(Encyclopedia)CE5 isoleucine īˌsəlo͞oˈsēn [key], organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer appears in mammalian protein. It is one of several es...

ectoderm

(Encyclopedia)ectoderm, layer of cells that covers the surface of an animal embryo after the process of gastrulation has occurred. This outer layer, together with the endoderm, or inner layer, is present in all ear...

Ectoprocta

(Encyclopedia)CE5 Bugula, a moss animal, representative of the phylum Ectoprocta Ectoprocta ĕkˌtəprŏkˈtə [key], phylum of sessile, colonial aquatic animals (commonly known as moss animals or oryonzoans). ...

dentition

(Encyclopedia)dentition, kind, number, and arrangement of the teeth of humans and other animals. During the course of evolution, teeth were derived from bony body scales similar to the placoid scales on the skin of...

chromosome

(Encyclopedia)chromosome krōˈməsōmˌ [key], structural carrier of hereditary characteristics, found in the nucleus of every cell and so named for its readiness to absorb dyes. The term chromosome is usually res...

selenium

(Encyclopedia)selenium səlēˈnēəm [key], nonmetallic chemical element; symbol Se; at. no. 34; at. wt. 78.96; m.p. 217℃; b.p. about 685℃; sp. gr. 4.81 at 20℃; valence −2, +4, or +6. Selenium is directly ...

serotonin

(Encyclopedia)serotonin sĕrˌətōˈnĭn [key], organic compound that was first recognized as a powerful vasoconstrictor occurring in blood serum. It was partially purified, crystallized, and named in 1948, and it...

poisonous plant

(Encyclopedia)poisonous plant, any plant possessing a property injurious to man or animal. Plants may be poisonous to the touch (e.g., poison ivy, poison sumac), or orally toxic (e.g., poison hemlock, deadly amanit...

prairie dog

(Encyclopedia)prairie dog, short-tailed, ground-living rodent, genus Cynomys, of the squirrel family, closely related to the ground squirrels, chipmunks, and marmots. There are several species, found in the W Unite...

phenylalanine

(Encyclopedia)CE5 phenylalanine fĕnˌəlălˈənēnˌ [key], organic compound, one of the 22 α-amino acids commonly found in animal proteins. Only the l-stereoisomer appears in mammalian protein. It is one of ...