Mammals have the following featuresThey have their bodies covered with hairHis limbs are usually shaped legs, allowing them to move. Aquatic mammals such as dolphins or whales have fins transformed into limbs and flying mammals like the bat in their membranes possess forelimbs that serve as wingsYour body temperature is constant, ie the body temperature does not change if you change the outside temperature. We say they are warm-blooded animals.They breathe with lungs, allowing them to take oxygen from the air. Aquatic mammals such as dolphins, need to take to the sea surface to take oxygen.His mouth has lips and teeth. Let lips sucking at the breast milk without causing damage. Some whales have no teeth, but some thin slices called barbs.


PoultryBirds have these characteristics:His body is covered with feathers.Their front legs are shaped like wings. Birds fly through the movements of their wings, though some birds can not fly, like ostriches or penguins.The skeleton is very light, since the bones are hollow. In addition, some birds have pouches called air sacs, which are filled with air and facilitate flight.Body temperature is constant, ie, they are warm-blooded animals.They breathe with lungs.The mouth has a toothless beak, which varies greatly from species to species as food.


Fish have the following characteristics:His body is covered with scales.His limbs are shaped fins. Your body ends in a stronger fin forming the tail.Its skeleton is the simplest of vertebrates. Most fish have bony skeleton, bones shaped spine. Some fish, like sharks and rays, have a cartilaginous skeleton, consisting of pieces soft and flexible bones called cartilage.Body temperature is variable, ie, depends on the temperature of water in which they are found. So we say they are cold blooded animals.Most fish have a swim bladder, which is like a bag full of air that prevents them from sinking.Fish breathe through gills, which are a group of thin plates arranged in several rows. The gills are located behind the head, and allow them to get the oxygen dissolved in water.


Amphibians have the following characteristics:Their skin is naked and wet.His limbs are muscular legs, allowing them to swim or jump.Body temperature is variable, ie, they are cold blooded animals.The young are born in water and breathe through gills, while the adults live on land and water, and breathe through their skin and lungs.They feed on insects, worms and other small animals.They are oviparous: they reproduce by eggs. Fertilization is usually external. The female lays eggs in water and the male fertilizes them, water the eggs stick together and form clusters bulky.Reptiles possess these characteristics:His body is covered with scales.His limbs are shaped legs, which are usually very short. Some reptiles, like snakes, have no legs.Your body temperature varies, ie, they are cold blooded animals. Therefore usually live in hot, and become dormant during winter.They breathe with lungs.Most are carnivores. In the mouth often have many teeth, all the same size, with those who hold their prey.They are oviparous, ie, reproduce by eggs.Their fertilization is internal. The male mates with the female and fertilized eggs are formed. the female lays eggs on the grass or buried.Some reptiles, like the snake are ovoviviparous: The eggs hatch within the body of the mother and pups are born alive.


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