Click on each box to find out more

1
(No Transcript)
2
Click on each boxto find out more
Natural Science 2. Secondary Education
3
Animals with no specialised parts for excretion

• Sponges and cnidarians eliminate waste through
  their body surface because most of their cells
  are in direct contact with the external
  environment.

A cnidarian (anenome) with no excretory system.
Go back to the Start menu
Natural Science 2. Secondary Education
4
Animals with specialised parts for excretion

• Excretion is carried out by
• The respiratory organs
• The excretory organs

Malpighian tubules
The respiratory system in a mammal
The excretory systemin an arthropod (Malpighian
tubules)
Go back to the Start menu
Natural Science 2. Secondary Education
5
Excretion in respiratory organs

• Respiratory organs play a role in excretion by
  expelling carbon dioxide from breathing.

CO2
The respiratory organs of an arthropod (tracheae)
Go back to the Start menu
Natural Science 2. Secondary Education
6
Excretion in excretory organs

• Excretory organs filter the circulating liquid,
  collecting the waste matter it carries. Later
  they eliminate this waste directly into the
  environment or they discharge it at the end of
  the digestive system, so it is eliminated along
  with indigestible food.
• Examples of excretory organs
• Kidneys (vertebrates)
• Malpighian tubules (insects and myriapods)
• Nephridia (many invertebrates)
• Antennae glands or maxillary glands
  (crustaceans)

The kidneysof a reptile
Go back to the Start menu
Natural Science 2. Secondary Education