Incomplete metamorphosis is a type of metamorphosis in which an insect hatches from an egg and then goes through several nymphal stages. Each nymphal stage …
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Coelom Definition The coelom is a body cavity found in metazoans (animals that develop from an embryo with three tissue layers: ectoderm, mesoderm, and endoderm). The cells in each tissue layer become differentiated during …
Zooplankton Definition Zooplankton (pictured below) are a type of heterotrophic plankton that range from microscopic organisms to large species, such as jellyfish. Zooplankton are found within …
Zoology Definition Zoology, or animal biology, is the field of biology that involves the study of animals. The word zoology comes from the Greek words zōion, …
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Vivisection Definition Vivisection is the use of live animals in scientific experiments. The term comes from the Latin word vivus which means alive and the English word section meaning …
Threatened Species Definition A threatened species is any species which is vulnerable, endangered, or critically endangered. The International Union for Conservation of Nature, or IUCN, is commonly referenced as a leading …
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Tertiary Consumer Definition A tertiary consumer is an animal that obtains its nutrition by eating primary consumers and secondary consumers. Usually tertiary consumers are carnivorous predators, although they may also …
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Sexual Dimorphism Definition Sexual dimorphism is when the genders of a particular species have different characteristics, not related to their sexual organs. On the other hand, a …
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Sessile Definition Biologically speaking, an organism that is sessile (as opposed to motile) lacks the ability of self-locomotion and is predominantly immobile. In zoology, sessility applies to those animals …
Definition Punctuated equilibrium is a theory that states that evolution occurs primarily through short bursts of intense speciation, followed by lengthy periods of stasis or equilibrium. …
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