prueba 2

1- The great animal kingdom It consists of all animals. Its main features are: - They feed on plants or other animals - They relate to the outside through the movements (walk, fly or swim) and through the sense organs The animals may be classified into two groups: - Vertebrates - Invertebrate Animals

2- Vertebrate Animals Are a group of animals with an articulated internal skeleton, which acts as support body and allowing their movement.

2.1- Features - They spine, formed by a series of joint parts or vertebrae, which allow some movement and give some flexibility - The body is divided into head, trunk and extremities - There individuals male and female individuals, that is, sex is differentiated

3- Classification of vertebrates The vertebrates are classified into five groups: - Mammals - Birds - Fish - Amphibians - Reptiles

3.1- Mammals - They have their hairy bodies.

- His limbs are generally shaped legs, which allow them to move. Aquatic mammals such as dolphins and whales have their fins transformed into limbs and flying mammals such as bat membranes have their forelimbs that serve as wings.

- Your body temperature is constant, ie, the body temperature does not vary if the outside temperature changes. We say they are warm-blooded animals.

- They breathe with lungs, allowing them to take oxygen from the air. Aquatic mammals such as dolphins, they need to surface of the sea to take oxygen.

- His mouth has lips and teeth. Lips to allow sucking milk sucking harmlessly.

Some whales do not have teeth, but thin slices called barbs.

3.2- Birds - Your body is covered with feathers.

- Their forelimbs are shaped wings. Birds fly through the motions of their wings, but some birds are unable to fly, like ostriches or penguins.

- The skeleton is very light, since the bones are hollow. In addition, some birds have some bags, 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.

3.3- Fish - Your body is covered with scales.

- His limbs are shaped fins. Your body ends in a stronger way the tail fin.

- His skeleton is the simplest of vertebrates. Most fish have a bony skeleton, with bone-shaped spine. Some fish, such as sharks and rays, have a cartilaginous skeleton, consisting of softer, flexible pieces that bones called cartilage.

- The body temperature varies, namely, depends on the temperature of the water in which they are. Therefore we say that they are cold-blooded animals.

- Almost all fish have a swim bladder, which is like a bag of air that prevents them from sinking.

- Fish breathe by gills, which are a group of thin sheets arranged in several rows.

The gills are located behind the head, and allow them to obtain the dissolved oxygen in the water.

3.4- Amphibians - Your skin is naked and wet.

- His limbs are muscular legs, which allow them to swim or jump.

- Body temperature is variable, ie, are cold-blooded animals.

- The young are born in water and breathe through gills, while adults live on land and in water, and breathe through their skin and lungs.

- They feed on insects, worms and other small animals.

- They are oviparous: reproduce by eggs. Fertilization is usually external. The female lays eggs in the water and the male fertilizes them. eggs in water sticking each other, and form bulky clusters.

3.5- Reptiles - Your body is covered with scales.

- His limbs are shaped legs, which are typically very short. Some reptiles, like

snakes do not have legs.

- Your body temperature is variable, ie, are cold-blooded animals. Therefore usually live in warm environments, and become dormant during the 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.

- Are oviparous, ie eggs are reproduced.

- Your 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 such as snake are ovoviviparous: The eggs hatch within the body of the mother and offspring are born live.