Transcript A38-Mammals
Mammals Mammals • Vertebrates (backbone), have hair, develop specialized teeth backbone Mammals • Have various glands, including mammary glands that produce milk • Endothermic (warm-blooded) • Can keep a stable temperature by using energy from food • Hair/fur and fat also provide insulation Mammals: Respiration • Use lungs to breathe • Diaphragm (at bottom of ribs) forces air into and out of lungs • In lungs, oxygen enters blood and carbon dioxide exits blood Mammals: Circulation • 4-chambered heart and 2 loops of vessels – keeps oxygen-rich blood completely separate from oxygenpoor blood • Blood also removes waste from cells and helps regulate body temperature Blue = oxygen-poor blood Red = oxygen-rich blood Mammals: Movement • Movement- varies with organisms – Walk on 2 or 4 limbs, hop, swing on vines, use flippers Mammals: Nervous System • Receives and interprets information from the environment • 5 senses: vision, hearing, smell, taste, and touch • Chemical and electrical signals travel to the brain, and the brain directs the action of the body OUCH! Mammals: Reproduction • Reproduce sexually through internal fertilization • Mammals are divided into 3 subclasses based on reproductive methods: Mammals: Reproduction 1. Placental mammals (90%) – give birth to young that have developed inside the mother’s uterus until the body systems are fully developed – Placenta – organ that passes nutrients and oxygen to baby and removes waste from baby through umbilical cord Placental Mammals Mammals: Reproduction 2. Marsupials – short period of development inside the mother’s body, then finishes development in a pouch – Ex.: opossum, kangaroo, koala Opossum embryos in a pouch Mammals: Reproduction 3. Monotremes – lay eggs – Only 3 (2 spiny anteaters and 1 duck-billed platypus) http://australianscreen.com.au/titles/echidna-survivor/clip3/