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eye

(Encyclopedia)CE5 Cross section of human eye eye, organ of vision and light perception. In humans the eye is of the camera type, with an iris diaphragm and variable focusing, or accommodation. Other types of ey...

North Atlantic Treaty Organization

(Encyclopedia)North Atlantic Treaty Organization (NATO), established under the North Atlantic Treaty (Apr. 4, 1949) by Belgium, Canada, Denmark, France, Great Britain, Iceland, Italy, Luxembourg, the Netherlands, N...

cell, in biology

(Encyclopedia)CE5 Animal cell cell, in biology, the unit of structure and function of which all plants and animals are composed. The cell is the smallest unit in the living organism that is capable of integrati...

Mollusca

(Encyclopedia)Mollusca məlŭsˈkə [key], taxonomic name for the one of the largest phyla of invertebrate animals (Arthropoda is the largest) comprising more than 50,000 living mollusk species and about 35,000 fos...

deafness

(Encyclopedia)deafness, partial or total lack of hearing. It may be present at birth (congenital) or may be acquired at any age thereafter. A person who cannot detect sound at an amplitude of 20 decibels in a frequ...

circulatory system

(Encyclopedia)CE5 Circulatory system circulatory system, group of organs that transport blood and the substances it carries to and from all parts of the body. The circulatory system can be considered as compose...

reproduction

(Encyclopedia)CE5 Examples of asexual reproduction reproduction, capacity of all living systems to give rise to new systems similar to themselves. The term reproduction may refer to this power of self-duplicati...

Cnidaria

(Encyclopedia)CE5 Internal anatomy of Hydra, representative of the phylum Cnidaria Cnidaria səlĕntəräˈtə [key], phylum of invertebrate animals comprising the sea anemones, corals, jellyfish, and hydroids....

snake, in zoology

(Encyclopedia)snake, common name for an elongated, limbless reptile of the order Squamata, which also includes the xlizards. Most snakes live on the ground, but some are burrowers, arboreal, or aquatic; one group i...

cancer, in medicine

(Encyclopedia)cancer, in medicine, common term for neoplasms, or tumors, that are malignant. Like benign tumors, malignant tumors do not respond to body mechanisms that limit cell growth. Unlike benign tumors, mali...