2.50: Understand the Need for Transport System in Multicellular Organisms

TRANSPORT SYSTEM: Means by Which Materials are Carried through a Medium to Constantly Supply Cells through an Exchange Surface E.g Transport System in Humans is Blood

MULTICELLULAR ORGANISMS: Organisms made of More than One Cell

MULTICELLULAR ORGANISMS AND TRANSPORT SYSTEMS:

UNICELLULAR ORGANISMS RELY ON DIFFUSION

Diagram Showing the Relation of Size and Surface Area to Volume Ratio

EXPLANATION: Multicellular Organisms Relies on Transport Systems to Move Substances Into and Out of Cells It has a Small Surface Area to Volume Ratio as they are Large (As Size Increases, Surface Area to Volume Ratio Decreases) as they have More than One Cell so has a Inefficient Rate of Diffusion So Relies on Transport Systems to Provide a Constant flow of Substances that it Needs such as Oxygen and Glucose

COMMON FEATURES OF TRANSPORT SYSTEMS: Tubes or ‘Vessels’ Carries Materials from One Part of the Organism to Another in a Structured Process     2. Close Contact with Cells Allows the Exchange of Materials through Exchange Surfaces     3. May have Pumps For Example, the Human Circulatory System has the Heart that Acts as an Pump to Ensure the Constant Circulation of Blood which is the Medium in Which Materials will be Transported By Plants Do Not have Pumps, They have a Xylem and Phloem Instead