BIOL 1202 : Bio1202Test3
Document Summary
Concept 32. 1: animals are multicellular, heterotrophic eukaryotes with tissues that develop from embryonic layers. List the five characteristics that combine to define animals. They lack cell walls but have cells held together by the structural protein, collagen. The zygote undergoes cleavage (successive mitotic division, without cell growth between divisions) and becomes a blastula, followed by gastrulation (the process in which layers of embryonic tissues that will develop into adult body parts are produced). Concept 32. 3: animals can be characterized by body plans : distinguish between radial and bilateral symmetry. Explain how animal symmetry may match the animal"s way of life. Radial symmetry- the organism has no front, back, left, or right. Often includes sessile animals, though if they move, i. e. jellies, their movements are weak. Bilateral symmetry- the organism has a right, left, front, and back. These organisms are good at moving: distinguish among acoelomate, pseudocoelomate, and coelomate grades.
