Biology 3484A/B Lecture Notes - Lecture 17: Skull, Anapsid, Fish Migration
27 Apr 2019
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It fills with amniotic fluid which causes the amnion to expand and become the amniotic sac which serves to provide a protective environment for the developing embryo or fetus. Sort each into higher taxa level: lungfish, lobe-finned fish, coelacanths, lobe-finned fish. Identify traits associated with: tetrapods, four limbs, some lost or vestigial, one bone two bones little blobs fingers/toes, some lost or vestigial. Internal fertilization, with females producing eggs every four years. Describe the differences in the bone structure of ray-finned and lobe-finned fishes: lobes may have conferred more controlled movement through shallow water, less dependent on tail, modification of bones in lobes gave improved strength. Describe the circulatory system of amphibians and reptiles: three-chambered heart, present in amphibians and reptiles, two atria, one ventricle, ridges in ventricle divert blood into correct circuit to prevent most mixing of oxygenated and deoxygenated blood. Describe the threats to the biodiversity of various amphibian and reptile taxa: climate change, temperature-dependent sex determination.
