BIOL 1510 Lecture Notes - Lecture 8: Homeothermy, Yolk Sac, Amniotic Sac
Document Summary
Chordates: are very related to invertebrates, all deutrostomes, evolved during the cambrian explosion, before plants, we were evolving in the water, a lot of evolutionary history evolve din water. History: chordate, plant, arthropods, tetropods (4 leg, amnioats (not lay eggs completely in water, mammals. Second arches- hyoid bone: post anal tail. How does the cell know where they are to know what they will become: by knowing where they are positioned then they know this by hox genes. Hox gene: humans have 4 sets, fish has 7 sets. Vertebrates: agnatha- jawless, gnathos- jaws, the most basic vertebrates don"t have jaws, the parthana, the conods, lamprey- muscular pharynx, the main sti ng body is still the notochord, had huge variability in the chards. Sharks: this is ampleaye of artencemy, neuronmass cells, can detect movement around the water because of the lateral line system and can detect your muscular impulses.
