BISC208 Lecture Notes - Lecture 12: Vertebral Column, Chordate, Blastomere
29 Aug 2016
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Document Summary
Multicellular but lack cell walls which allows more flexibility. Anchoring, tight, and gap junctions play role in binding cells and communication. Structural support from extracellular matrix- strong fibers such as collagen outside cell: mode of nutrition. Animals are heterotrophs- ingest other organisms or their products to sustain life/ obtain organic molecules. Modes of feeding including suspension, bulk, and fluid feeding: movement. Animals have nervous tissue which coordinates movement with muscle tissue: genomes. All animals have hox genes which pattern the body axis. Have similar genes that encode for rna of rrna: reproduction and development. Nearly all members reproduce sexually, egg fertilized by sperm to form zygote. Can occur internally usually for land animals and externally for aquatic animals. The animal kingdom is monophyletic- all taxa have evolved from a single common ancestor. About 35 animal phyla today but 11 main phyla exist. Animals evolved from increase in atmospheric oxygen which permitted higher metabolic rates and increased activity.
