Chapter 5: Vertebrates

Vertebrates Animals with backbones All vertebrates have an endoskeleton, an internal support system that makes the animal more flexible and easier to move. The 5 groups are birds, fish, amphibians, reptiles, and mammals.

Fish Have gills, a respiratory organ that filters oxygen dissolved in water. Have sensory organs for taste, odor, and sound. Female fish lay eggs that are fertilized by a certain male. Eggs develop and hatch on their own

Amphibians Lay eggs in water Smooth, moist skin Skin works as a respiratory organ only when wet. Can live in moist land environments as adults. Ex: Frogs, toads, salamanders

Reptiles Tough, dry skin covered by scales Obtain oxygen from air with lungs Lay eggs, which have shells, on land. Ex: snakes, lizards, alligators

Ectotherms Amphibians and reptiles are ectotherms, animals whose body temperatures changes with environmental conditions. For example, on a cool day, a tortoise’s body will be cooler than it is on a hot one.

Birds Have feathers and beaks Have a pair of scaly legs and a pair of wings Their eggs have hard shells. Mothers sit on their eggs to keep them warm (incubation) Hollow bones

Mammals Have hair or fur Contain body fat to store energy or maintain body temperature Females produce milk to feed their young In most mammals, offspring develop inside the female’s body

Endotherm Bird and mammals are endotherms, which means their body maintains a constant body temperature. Birds and mammals have many adaptations to help maintain body temperature