Circulatory System

Question 1

Large Organsims

Answer 1

They can’t diffuse because of a low surface area : volume ratio, meaning diffusion alone is not adequate

Question 2

4 Main Blood Types

Answer 2

Red blood cells, White blood cells, Plasma and Platelets

Question 3

Red Blood Cells

Answer 3

They’re biconcave cells that contain the red pigment haemoglobin and carry oxygen around the body in the blood. There are 5-6 million red blood cells per each cubic millimetre of blood

Question 4

White Blood Cells

Answer 4

They’re blood cells involved in the immune system of the body. They engulf pathogens and make antibodies and antitoxins. They’re larger than red blood cells and they have a nucleus

Question 5

Plasma

Answer 5

It’s the clear yellow-liquid part of the blood that carries dissolved substances and blood cells around the body

Question 6

Platelets

Answer 6

They’re fragments of cells in the blood that play a vital role in the clotting mechanism of the blood

Question 7

Arteries

Answer 7

They’re blood vessels that carry blood away from the heart. They usually carry oxygenated blood and have a pulse

Question 8

Veins

Answer 8

They’re blood vessels that carry blood away from the heart. They usually carry deoxygenated blood and have valves to prevent the backflow of blood

Question 9

Cappilaries

Answer 9

They’re the smallest blood vessels. They run between individual cells and have a wall that is only one cell thick