Post on 28-Nov-2014
description
Animals can be classified into groups, according to their characteristics.
Most mammals
are warm-blooded
have hair or fur
give birth to live young
feed their babies with mother's milk
MAMMALS
Most reptiles and amphibians
have lungs for breathing
are cold-blooded
give birth to young hatched from eggs
REPTILES and AMPHIBIANS
Reptiles and amphibians are "cold-blooded." This doesn't mean they have cold blood, but that they don't produce their own heat like mammals. They need to get heat from the sun to warm themselves.
So what's the difference between reptiles and amphibians?
have dry, rough, scaly skin
lay their eggs on or under dry ground
begin their life cycle on land
have moist, smooth skin without scales
lay eggs in water or in damp areas
begin their life cycle in water and then, as adults, their bodies change to adapt to life on dry land
Most birds
have two wings, two legs and a beak
are covered with feathers
are warm-blooded
give birth to babies hatched from eggs
BIRDS
Most insects and arachnids
- have hard outer shells called exoskeletons
- have multiple pairs of legs
- breathe through holes in the sides of their bodies
- are cold-blooded
- give birth to young hatched from eggs
INSECTS and ARACHNIDS
Most fish
live in water all their lives
breathe oxygen from water through special organs called gills
have fins and scales
are cold-blooded
give birth to babies hatched from eggs
FISH