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Pygmy

(Encyclopedia)Pygmy or Pigmy both: pĭgˈmē [key], term used for dark-skinned people who live in equatorial rain forests and average less than 59 in. (150 cm) in height. Some studies make a distinction between Neg...

AZT

(Encyclopedia)AZT or zidovudine zīdōˈvyo͞odēnˌ [key], drug used to treat patients infected with the human immunodeficiency virus (HIV), which causes AIDS; also called azidothymidine. Originally developed in 1...

Nematoda

(Encyclopedia)Nematoda nĕmˌətōdˈə [key], phylum consisting of about 12,000 known species, and many more predicted species, of worms (commonly known as roundworms or threadworms). Nematodes live in the soil an...

whale

(Encyclopedia)whale, aquatic mammal of the order Cetacea, found in all oceans of the world. Members of this order vary greatly in size and include the largest animals that have ever lived. Cetaceans never leave the...

Neanderthal man

(Encyclopedia)Neanderthal man –tôlˌ [key], a species of Homo, the genus to which contemporary humans belong, known as H. neandertalensis after Neanderthal (now Neandertal), Germany, the valley where the first s...

aging

(Encyclopedia)aging, in biology, cumulative changes in an organism, organ, tissue, or cell leading to a decrease in functional capacity. In humans, aging is associated with degenerative changes in the skin, bones, ...

multiple birth

(Encyclopedia)multiple birth, bringing forth of more than one offspring at birth. Although many smaller mammals bear several young at a time, multiple births are relatively uncommon in humans and other primates. Tw...

cystic fibrosis

(Encyclopedia)cystic fibrosis sĭsˈtĭk fībrōˈsĭs [key], inherited disorder of the exocrine glands (see gland), affecting children and young people; median survival is 25 years in females and 30 years in males...

chimpanzee

(Encyclopedia)chimpanzee, an ape, genus Pan, of the equatorial forests of central and W Africa. Smaller populations are also found in the savannas of the same regions. The common chimpanzee, Pan troglodytes, lives ...

clone

(Encyclopedia)clone, group of organisms, all of which are descended from a single individual through asexual reproduction, as in a pure cell culture of bacteria. Except for changes in the hereditary material that c...