BIO153H5 Study Guide - Final Guide: Radula, Neural Crest, External Fertilization
Document Summary
Characteristics of animals animals are the only one on tree of life with muscular tissue and nervous tissue reproduce both sexually and asexually (no alternation of generations) diploid adults, the only haploid cells are gametes produced during sexual reproduction. All triploblastic animals have bilateral symmetry except for echinodermata (radial symmetry involved independently of diploblastic groups. Larva is bilaterally symmetrical however adult echinoderm is radially symmetric) *coelom acts as a hydrostatic skeleton which allows movement even without fins/limbs. *by providing hydrostatic skeletons, evolution of coelom gave bilaterally symmetric organisms the ability to move: how do the events in embryo development proceed except for adult echinoderms (radially symmetric, diploblasts), all coelomates are triploblastic and bilaterally symmetrical. Cleavage: series of mitotic divisions that occur in the absense of growth protostomes: spiral cleavage deuterostomes: radial cleavage. Gastrulation: cell movements that form three embryonic tissue layers (begins when cells move into the centre of embryo for both protostomes and deuterostomes)
