- Most cells get energy via anaerobic respiration.
- Glucose and Oxygen are needed for this - the body needs to supply this to all cells.
In single-celled organisms they can diffuse across the cell membrane to the cell. Rate of diffusion = quick as they only have a short distance to travel.
In multi-cellular organisms diffusion across the membrane is too slow - the distance is too far.
SO THEY HAVE A MASS TRANSPORT SYSTEM (OR CICULATORY SYSTEM)
- to carry raw materials from exchange organs to body cells.
- to remove waste EG carbon dioxide.
- in mammals blood is used to transport substances around the body.
THE HEART PUMPS BLOOD AROUND THE BODY - EACH PART OF IT IS ADAPTED FOR ITS JOB.
- LEFT VENTRICLE: thicker than right ventricle, as it needs to pump blood all the way around the body. Right only pumps blood…