The Need for a Transport system Flashcards
Why do animal cells need a supply of oxygen and nutrients?
To grow and survive
Why do they need to remove waste products?
do not build up and become toxic
Why do very small animal not require a separate transport system?
because all cells are surrounded by or very close to the environment in which they live.
How do small animals get their sufficient supply of oxygen and nutrients?
Diffusion
What is defined as a larger animal?
A complex anatomy will have more than 2 layers of cells.
the diffusion distance becomes too long, and diffusion is not sufficient to supply all the oxygen and nutrients needed to keep the cell alive.
State the three main factors that affect the need for a transport system
Size
SA:Vol ratio
Level of Metabolic Activity
Explain how size affects the need for a transport system
The cells inside a larger organism are further from it s surface - the diffusion pathway is increased.
the diffusion rate is reduced, and diffusion is too slow to supply all the requirements.
ALSO, the cells closer to the surface will use up all the nutrients and oxygen before it has a chance to reach the inner cells.
Explain how SA: Vol ratio affects the need for a transport system
A smaller animal
Has larger SA: vol ratio
Means for every gram of tissue - they have a sufficient area of body surface through which exchange can happen
Explain how the level of metabolic activity affects the need for a transport system
Animals need energy from food to supply energy for movement.
Releasing energy from food by aerobic respiration requires oxygen.
If an animal is very active, its cells needs as much oxygen and nutrients as possible to supply the cells with enough energy for moving about.
Animals that keep themselves warm, such as mammals, require even more energy.
