01:119:101 Lecture Notes - Lecture 21: Monophyly, Mesoderm, Cambrian Explosion
25 Feb 2016
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Document Summary
Characteristics of animals: multicellular, eukaryotic, cells no cell walls, heterotrophs ingest food, differentiated cells, most have differentiated tissues. Group of cells that act as a functional unit: higher forms. Differentiated organs specialized structures made up of specialized tissues adapted to perform a specific function: muscle and nerve tissue. Movement and nerve impulses: bodies held together by structural proteins, reproduction. Diploid stage = dominant stage in life cycle: meiosis, fertilization. Sperm egg zygote (2n: embryonic development, cleavage series of mitotic cell divisions without cell growth between divisions, blastula typically a hollow ball of cells that surround a cavity called blastocoel, gastrulation process in which, gastrula. Archenteram pouch that opens to outside via opening called the blastopore: some animals. Have atleast 1 larva stage: larva sexually immature but morphologically different from adult, different foods and habitats than adults stage, metamorphosis juvenile (not sexually mature) Development regulated by gene expression: homeobox genes code for proteins that regulate expression of developmental genes, ex.
