BIOL 211 Lecture Notes - Lecture 6: Deuterostome, Blastocoel, Egg Cell
Document Summary
These tissues are not in plants or fungi. Gametes are produced by meiosis and are typicallt the only haploid cells in the lifecycle. Early embryonic development includes cleavage, blastula stage, gastration, and gastrula stage. It is quite similar to the morphological phylogeny that preceded it (pre-1997) All animals are come from a single origin= monophylitic. Sponges are basal (at the base of kingdom animalia) Divided into: parazoa (no specialized tissues or organs) Eumetazoa (more than one type of tissue and organs) Collections of specialized cells isolated from other tissues by membranous layers. Cleavage-mitotic cell division w/o cell growth (no change in cell size) Fertilized egg cell a ball of cells (blastula) (hollow) Gastrulation- a rearrangement of the embryo; folds into the blastocoel, formation of layers (i. e. germ layers) the ball starts to fold in on itself and creates a little hole. Radial: you can cut it in many ways and have similar sections.
