blood

Question 1

blood

Answer 1

• blood plasma 55%
• blood cells and platelets 95%

Question 2

blood plasma

Answer 2

water with plasma proteins and dissolved substances. 91% water, 7% plasma proteins, 2% dissolved substances.
- transports oxygen, nutrients, antibodies, carbon dioxide and other waste products
- fibronigen plays a role in clotting

Question 3

red blood cells

Answer 3

• cells without nucleus
• red cells contain the red pigment haemoglobin
• transports oxygen
• anaemia: the blood contains too little heamoglobin, this can make you feel weak and tired all the time.

Question 4

white blood cells

Answer 4

• cells with nucleus
• don’t have a fixed shape; they can pass through the capillary walls.
• protection against pathogens, for instance by encapsulating bacteria.

Question 5

platelets

Answer 5

• fragments of cells that have broken up, no nucleus
• coagulation (clotting)