| A | B |
|---|
| chordate | animals with a notochord, hollow nerve chord in back, and gill slits |
| endoskeleton | inside the body |
| endotherm | animals with a constant body temperature - humans, whales, birds, etc. |
| ectotherm | animals with body temperatures that change with their surroundings |
| fish | ectotherms that live in water and breathe oxygen through gills |
| fins | most fish use these for steering, balancing, and moving |
| cartilage | tough, flexible, similar to bone but not hard |
| 3 types of fish | bony, jawless (lamprey), cartilaginous (shark, stingray) |
| amphibians | vertebrate ectotherms that spend part of their lives in water and part on land |
| hibernation | a period of inactivity during the winter |
| estivation | a period of inactivity during hot, dry, summer months |
| reptile | ectotherms, vertebrates with dry, scaly skin; they do not depend on water for reproduction; lay leathery eggs |
| bird | endotherm vertebrates with 2 legs, 2 wings, bills or beaks, and feathers; they lay hard-shelled eggs |
| contour feathers | strong, lightweight; give the bird its coloring and shape |
| down feathers | soft and fluffy; provide insulation; next to the skin of adults and cover the body of young birds |
| mammals | endothermic vertebrate that has hair and produces milk to feed its young |
| monotreme | mammal that lays eggs with tough, leathery shells; the duck-billed platypus and two species of spiny anteaters |
| marsupial | mammal that gives birth to immature offspring and that has a pouch in which its young complete their development |
| placental mammals | mammals whose embryo develops in the uterus of the female |
| herbivore | grazing animal that eats only plants |
| carnivore | flesh-eating animal |
| omnivore | animal that eats both plants and animals |
