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larva, in zoology

(Encyclopedia)larva, independent, immature animal that undergoes a profound change, or metamorphosis, to assume the typical adult form. Larvae occur in almost all of the animal phyla; because most are tiny or micro...

drug resistance

(Encyclopedia)drug resistance, condition in which infecting bacteria can resist the destructive effects of drugs such as antibiotics and sulfa drugs. Drug resistance has become a serious public health problem, sinc...

embryo

(Encyclopedia)CE5 Development of the human embryo embryo ĕmˈbrēō [key], name for the developing young of an animal or plant. In its widest definition, the embryo is the young from the moment of fertilizatio...

artificial insemination

(Encyclopedia)artificial insemination, technique involving the artificial injection of sperm-containing semen from a male into a female to cause pregnancy. Artificial insemination is often used in animals to multip...

Rothamsted

(Encyclopedia)Rothamsted rŏthˈəmstĭd [key], world's oldest and England's most important agricultural experiment station, now the main center of the Institute of Arable Crops Research (IACR). It was founded in 1...

reaper

(Encyclopedia)reaper, early farm machine drawn by draft animals or tractor and used to harvest grain. Its historical predecessors were the sickle and the cradle scythe, which are still used in some parts of the wor...

threonine

(Encyclopedia)CE5 threonine thrēˈənēn [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 several essen...

scale, in zoology

(Encyclopedia)scale, in zoology, an outgrowth, either bony or horny, of the skin of an animal. The major component of the scales of fishes is bone, and they are formed directly in the skin membrane as the fish grow...

Great Limpopo Transfrontier Park

(Encyclopedia)Great Limpopo Transfrontier Park, c.13,500 sq mi (35,000 sq km; roughly the size of Belgium), the largest multinational park in S Africa and one of the largest parks in the world, in NE South Africa, ...

onager

(Encyclopedia)onager ŏnˈəjər [key] or Persian wild ass, wild ass of central Asia, Equus hemonius onager. Formerly classified as a separate species, it is one of the several subspecies of Asian wild ass (E. hemo...