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THEME A : INVESTIGATING LIVING THINGS

UNIT 2 : LIVING THINGS UNDERGO LIFE PROCESSES

TOPIC : LIFE PROCESSES IN ANIMALS

The animal life processes are :

• excretion
• breathing
• reproduction

EXCRETION :

1.   Animals excrete and defecate to remove waste products, undigested food and excess water from their bodies.

2.   Animals excrete three waste products which are :

• sweat
• urine
• exhaled air

3.  Different animals have different excretory organs.
4.  The lungs of land animals remove carbon dioxide and water vapour.
5.  Examples of such animals are snakes, birds cows and bats. 

6.  The gills of aquatic animals remove carbon dioxide and water vapour.
7.  Examples of such animals are tadpoles, fish and crabs.

8.  The trachea of insects also remove carbon dioxide and water vapour.
9.  Examples of such insects are ants, grasshapper and cockroaches.

10.  The kidneys of animals remove urine.
11.  Examples of such animals are monkeys, cats and cows.

12.  The skin of some land animals such as cows, horses and elephants, remove water in the form of sweat.

13.  The excretory organs of animals are lungs, gills, trachea, kidneys and skin.


DEFECATION :

1.   Faeces is removed through defection.
2.   Most animals remove faeces througgh the anus.
3.   Animals' waste products and faeces are poisonous. An animal will become very sick and may even die if waste products are not removed from its body.