structure of the blood is related to its function:

Question 1

red blood cells

Answer 1

transport O2 from lungs to tissue
transport CO2 from tissue to lungs

no nucleus- more space for haemoglobin

the centre of the cell, biconcave disc- greater surface area so that oxygen can diffuse in and out quickly.

Question 2

white blood cells

Answer 2

There are two types of white blood cell:

Phagocytes which surround, engulf and destroy pathogens.

Lymphocytes which produce antibodies that stick pathogens together. This makes it easier for phagocytes to destroy the pathogens.

Question 3

platelets

Answer 3

Platelets form scabs to seal the skin and keep infection out

Question 4

plasma

Answer 4

It is mainly made of water and is pale yellow so is often called ‘straw-coloured’.

It also carries hormones, dissolved glucose for respiration, dissolved salts and enzymes around the body. Waste products like carbon dioxide are also transported in the plasma.