MAMMALS

They are heterothops, they don´t produce their own organic matter. They can be carnivores, herbivores or omnivores.

FEEDING: consists of taking in food.

DIGESTION: is a process carried out by animals, it cosists of transforming food into nutrients. DIGESTIVE TRACS: the mouth and the anus.

RESPIRATION: they take oxygen from the air. LUNGS: are two sponge-like organs made up of millions of alveolis.

CIRCULATION: They have a ciculatory system with a circulating fluid, vessels and a pumping mechanism (a heart). Closed circulatory system: this means that the circulating fluid never leaves the inside of the vessels.

EXCRETION: the excretory organs filter the circulating fluids ofthe animals and pic up any waist they are carrying.

Animals can move, they have well-developed organs of locomotion and muscle system.

RECEPTORS: Hearing organs (ears), balance organs and skin.

COORDINATION: The nervous system is responsible for receiving signals by the sense organs, interpreting them and generating orders to enable coordinated responses. This is sent by NEURONS, that are cells specialised in transmitting information.

EFFECTORS: Muscles enable living things to move.

They reproduce with sexual reproduction, they are viviparous. To reproduce they need gametes. Male gonads are called testes. They produce spermatozoa, are small, elongated structures witha flagellum. Female gonads are ovaries. They produce ova, are spherical and immobile.

- HAIR: this layer protects them fom the cold. They maintain their body´s temperature. - Females have MAMMARY GLANDS that produce milk. - They have lips and teeth. - Have a highly-developed nervous system.

MONOTREMES: Lay eggs with shells. HAVE: webbed feet, bill or beak and a flat tail. Their mammary glands don´t have teats.

MARSUPIALS: Are viviparous, give birth at a very early stage. They continue their development inside the pouch.

PLACENTALS: the young is connected to the mother by the placenta and are born fully developed.