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parthenogenesis

(Encyclopedia)parthenogenesis pärˌthənōjĕnˈəsĭs [key] [Gr.,=virgin birth], in biology, a form of reproduction in which the ovum develops into a new individual without fertilization. Natural parthenogenesis ...

swimming

(Encyclopedia)swimming, self-propulsion through water, often as a form of recreation or exercise or as a competitive sport. It is mentioned in many of the classics in connection with heroic acts or religious rites....

amphibian, in zoology

(Encyclopedia)amphibian, in zoology, cold-blooded vertebrate animal of the class Amphibia. There are three living orders of amphibians: the frogs and toads (order Anura, or Salientia), the salamanders and newts (or...

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...

tunicate

(Encyclopedia)tunicate to͞oˈnəkĭt [key], marine animal of the phylum Chordata, which also includes the vertebrates. The adult form of most tunicates (also called urochordates) shows no resemblance to vertebrate...

buttercup

(Encyclopedia)CE5 Common buttercup, Ranunculus acris buttercup or crowfoot, common name for the Ranunculaceae, a family of chiefly annual or perennial herbs of cool regions of the Northern Hemisphere. Thought to...

Twain, Mark

(Encyclopedia)Twain, Mark, pseud. of Samuel Langhorne Clemens, 1835–1910, American author, b. Florida, Mo. As humorist, narrator, and social observer, Twain is unsurpassed in American literature. His novel The Ad...

children's book illustration

(Encyclopedia)children's book illustration, any type of picture or decorative work produced for books specifically intended for a youthful audience. During the 1960s a number of seldom-used techniques were introd...

electricity

(Encyclopedia)CE5 Electrical and radio symbols electricity, class of phenomena arising from the existence of charge. The basic unit of charge is that on the proton or electron—the proton's charge is designate...

Chordata

(Encyclopedia)CE5 Common features in representative groups of the phylum Chordata Chordata kôrdāˈtə, –däˈ– [key], phylum of animals having a notochord, or dorsal stiffening rod, as the chief internal ...

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