BIOLOGY-MODULE 3 TRANSPORT IN ANIMALS: TRANSPORT SYSTEMS IN MULTICELLULAR ANIMALS

Why are transport systems needed?

1) To supply Oxygen and Nutrients

2) To remove Waste products

Why is there a need for specialised transport systems for multicellular organisms?

The bigger the organism, the greater the diffusion pathway. Without specialised transport systems, diffusion will occur but at too slow of a rate for the organism to survive

Specialised transport systems are needed due to ?

1) Meet high metabolic demands of multicellular organism

2) SA:V ratio gets smaller as multicellular organism gets bigger; so SA decreases and diffusion pathway increases

3)Production of molecules (hormones/enzymes) made in a 1 location yet needed in another

4) Waste product removed and transported to excretory glands

Specialised transport systems (circulatory system) carries ……. around the body?

Oxygen

Carbon dioxide

Nutrients

Waste products

Hormones

Circulatory system features:

1) Blood (liquid transport medium)

2) Vessels to carry transport medium

3) Pumping mechanism to move fluid around system

Open circulatory system

Closed circulatory system

Single closed circulatory system

Double closed circulatory system