4.1 Organising animals and plants

Question 1

What do red blood cells do?

Answer 1

contain haemoglobin that binds to oxygen to transport it from lungs to the tissues

Question 2

Why is it not accurate to describe the blood as a red liquid? What makes the blood red?

Answer 2

The liquid part of the blood is plasma which is yellow. The red pigment is what makes it look red.

Question 3

What do white blood cells do?

Answer 3

They protect the body against infection.

Question 4

What are the main components of blood? (and % in the blood)

Answer 4

• plasma 55%
• white blood cells and platelets <1%
• red blood cells 45%

Question 5

What are platelets?

Answer 5

They are cell fragments that start the clotting process at wound sites.

Question 6

What makes up the human circulatory system?

Answer 6

blood
blood vessels
heart

Question 7

Name three important functions of blood plasma?

Answer 7

• Plasma transports all your blood cells and some other substances around your body.
• Waste carbon dioxide is carried to the lungs
• Urea formed in your liver from the breakdown of excess proteins is carried to kidney - then removed in urine.
• Small soluble products of digestion pass into the plasma and transported to cells

Question 8

What does plasma do? What colour is it?

Answer 8

Blood plasma is yellow. It transports everything you need - and need to get rid of around your body.

Question 9

What are the three main functions of blood?

Answer 9

• transport - proteins and other chemicals around the body.
• protection - white blood and platelets
• regulation - water balance in different organs

Question 10

What adaptions do red blood cells have? (they make them more efficient)

Answer 10

• Biconcave discs (push in on the bottom side) give them an increased surface area
• Packed with red pigments (haemoglobin) that binds to oxygen
• No nucleus - makes more space for haemoglobin