Circulatory Systems (1.1)

Question 1

State the different types of circulatory system an organism can have

Answer 1

An organism could have a: closed double, closed single, open single or none (which relies on diffusion)

Question 2

Explain the reasons why there are different types of circulatory system

Answer 2

All organisms have different metabolic rates so require different systems. Organisms will also have systems best suited to pump blood to the outer extremities of their body in relation to their SA:V

Question 3

Explain the advantages of an organism having a double circulatory system

Answer 3

Allows blood to reach outer extremities of the body due to blood being pushed at high pressure.
Also allows a variation in pressure. Low pressure to lungs (prevents damage) and high pressure (for rest of body)

Question 4

Describe the difference between mass flow and diffusion

Answer 4

Mass flow = movement of liquid in one direction through a contained vessel from a high pressure to a low pressure
Diffusion = random movement of particles down the concentration gradient

Question 5

Explain why certain organisms need a mass flow system

Answer 5

Bring substances quickly from one exchange site to another. Maintain the diffusion gradients at exchange sites and between cells and their fluid surroundings. Ensure effective cell activity by keeping the immediate fluid environment of cells within a suitable metabolic range.