Circulatory System - Blood

Question 1

what is the job of a red blood cell

Answer 1

to carry oxygen from the lungs to all the cells in the body

Question 2

features of a red blood cell

Answer 2

shape - biconcave disc (doughnut) - gives a large surface area for absorbing oxygen
they don’t have a nucleus - allows more room to carry oxygen
contain red pigment called haemoglobin

Question 3

what does haemoglobin do

Answer 3

binds to oxygen to become oxyhaemoglobin.
in body tissues, the reverse happens - oxyhaemoglobin splits into haemoglobin and oxygen, to release oxygen to the cells

Question 4

what do white blood cells do

Answer 4

1) defend against infection and disease
2) some white blood cells can change shape to gobble up unwelcome microorganisms, in a process called phagocytosis
2) others produce antibodies to fight microorganisms, as well as antitoxins to neutralise any toxins produced by microorganisms
3) they have a nucleus

Question 5

what are platelets and what do they do

Answer 5

1) platelets help blood clot - stop all your blood pouring out and to stop microorganisms getting in
2) these are small fragments of cells. no nucleus
3) lack of platelets can cause excessive bruising and bleeding

Question 6

what is plasma and what does it do

Answer 6

1) liquid that carries everything in the blood
pale straw-coloured liquid which carries just about everything:
1) Red and white blood cells and platelets
2) nutrients like glucose and amino acid
3) CO2 from organs to the lungs
4) Urea from liver to kidneys
5) hormones
6) proteins
7) antibodies and antitoxins produced by WBC