Animal Diversity 1

• characteristics of animals: heterotrophy, cell structure and organization, reproduction and development
• cell structure and organization: eukaryotic, multicellular, no cell walls
• extracellular matrix: protein outside of cell membrane, connects and supports cell, mostly made of collagen
• differentiated cells: specialized function, more efficient
• differentiated tissue: groups of cells with common structure and function
• derived trait of MOST animals: muscle and nerve tissue
• differentiated organs: specialized structure made up of tissues
• reproduction is usually sexual
• fertilization: small flagellated sperm fuses with larger, non-motile egg creates zygote
• cleavage: mitotic division without growth
• blastulation: cell migration -> hollow ball
• blastula: hollow ball of cells around blastocoel
• gastrulation: process of inward folding of blastula
• blastopore: first opening
• archenteron: early digestive system for embryo
• homeobox genes (derived): code for proteins that regulate expression of developmental genes
• bilateral symmetry: any plane through longitude axis - halves
• bilateral symmetry: only 1 plane through longitude axis - halves
• germ layers: concentric layers of embryonic tissue, form during gastrulation
• ectoderm: outer covering nervous system
• endoderm: inner layer, lines digestive tube
• mesoderm: middle layer
• diploblasts: endoderm and ectoderm
• triploblast: endoderm, ectoderm, mesoderm
• body cavities only apply to triploblasts
• coelom: fluid-filled space between the body wall and digestive tube
• true coelomate -> pseudocoelomate -> acoelomate
• protostome development: spiral determinate cleavage, blastopore -> mouth
• deuterostome development: radial indeterminate cleavage, coelom formed by folds of the archenteron, blastopore -> anus
• sister taxon to animals: choanoflagellates
• eumetazoa derived trait: tissues, symmetry
• bilateria derived trait: bilateral symmetry, triploblasty
• nephrozoa derived trait: coelom, excretory structures
• deuterostomia derived trait: deuterostome development
• protostomia derived trait: protostome development
• spiralia derived trait: no specific
• ecdysozoa derived trait: ecdysis - molting/shedding of exoskeleton/cuticle