Blood

Question 1

4 main things in blood and broadly what do they do ?

Answer 1

Red blood cells -carry oxygen
White blood cells - defend against infection

Platelets - clot blood
Plasma - liquid that carries everything in blood

Question 2

Red Blood Cell
Purpose
Describe shape/structure (at least 3 points)
What is haemoglobin, what happens in lungs and then in body tissues

Answer 2

Carry oxygen from lungs to cells in body
Bioconcave 9like doughnut)
Large surface area (helps absorb oxygen)
No nucleus
Haemoglobin is a red pigment
In lungs haemoglobin binds with oxygen to form oxyhemoglobin
In body tissues, reverse: oxyhemoglobin splits into haemoglobin and oxygen to release oxygen to cells

Question 3

Purpose of White Blood cells
What 2 main things do they do
How do they differ from red blood cell

Answer 3

Some change shape and gobble up unwelcome microorganisms - Phagocytosis (phagocytes) - immune response
Other produce antibodies to fight microorganisms as well as antitoxins to neutralise toxins
They have a nucleus

Question 4

What do platelets do
Describe structure (2 points)
What would lack of platelets lead to

Answer 4

Help clot blood - stop blood pouring out and microorganisms getting in
Small fragments of cells, no nucleus
Lack of platelets can cause excessive bleeding and bruising

Question 5

What does plasma do
Describe plasma
What does it carry (at least 9 points)

Answer 5

Pale straw coloured liquid
Carries just about everything in blood

Red & white blood cells
Platelets
Nutrients eg glucose and amino acids (products of digestion absorbed from gut and taken to cells)
Co2 from organs to lungs
Urea - from liver to kidneys
Hormones
Proteins
Antibodies and antitoxins produced by white blood cells