BIO153H5 Midterm: AfterMidterm2Notes.pdf
Document Summary
At some point, all species in the phylum chordate have: Brains protected by a cranium: hag sh are scavengers and predators - they deposit feed. Lamprey are ectoparasites: well developed notochords that aid in swimming, lampreys are anadromous, spend most of the life in the ocean, and the swim upstream to mate. Mammals are endotherms that have hair or fur to insulate the body. Mammals are a class with three subclasses (figure 34. 30) Monotremes are the most ancient group of mammals living. They lay eggs and have lower metabolic rates than other mammals. Marsupial females have a placenta, but the young are born poorly developed after a short embryonic period. They continue to develop while attached to their mother"s nipple, where they suck milk. They stay attached to their mother until they grow large enough to move independently. Placental mammals are the most species rich and morphologically diverse group of mammals.
