science form 3

2. Contents of blood and their functionsContents of blood and their functions
• Under a microscope, blood cells float in a fluid
called plasma.
Blood consists of:
a.Plasma
b.Red blood cell
c. White blood cell
d.Platelets
(blood clotting
cells)

4. a) Plasma
• a liquid part of the blood.
• yellowish in colour
• alkaline characteristic
• sticky
• made up of water
• produce in the liver

5. a) Plasma contains:
• Dissolved substances like:
i. mineral salts
ii. Digested food
iii. Waste product
iv. Vitamins
v. Hormones
vi. Antibodies
vii. Gases
viii. Water

6. The function of plasma are:
a.Transport digested food to the cells
b.Transport waste products like urea from
the body tissue to the excretory organ.
c. Control the body temperature
d. To carry hormones to tissue.

8. b. Red blood cell
•Have biconcave shape
•Do not have nucleus
•Function: to transport
oxygen to body cell

9. b. Red blood cell
•Contain hemoglobin (red
pigment) which combined
with oxygen to form
oxyhemoglobin.
•Produce in bone marrow
•Lifespan: 4 months then
destroy in the liver and
spleen

11. b. White blood cell
•Larger size than red blood
cell
•Have nucleus
•Do not have a definite
shape
• Produce in bone marrow
and lymph glands

12. b. White blood cell
•Function: to protect the
body from being attacked
by microorganisms like
bacteria and viruses.
•(body defense system)

13. b. White blood
cell can:
a)Kill bacteria in blood
b)Produce antibodies to
neutralize poisonous
substance (toxin)
produce by
microorganisms.

15. d. Platelets • No definite shape
• Do not have nucleus
• Very small in size

16. • Function: to clot blood in
a wound to prevent the
lost of excessive amount
of blood.
• Produce in bone marrow
• Lifespan: very short- few
hours to 9 days
d. Platelets

18. OAB BA

19. •Human blood can be classified to 4 groups:
A, B, AB,O
Blood donor
•A person who donates his
blood to another
Blood recipient
•A person who receives
blood from another

20. •The blood recipient and the donor must be compatible.
If not the blood will be coagulate and the recipient
will die.
•The Blood group ‘O’ are called universal donor.
•blood must be screening before transfusion
Can donate People Can receive
O, A, B, AB O O
A, AB A O, A
B, AB B O, B
AB AB O, A, B, AB

21. •The lost of a lot of blood
From accident or operation
Needs to be replace by
Blood transfusion.
•People are encourage to donate blood to save others.
•2 types of blood transfusion:
a) through blood kept in blood bank
b) through direct channeling from the donor to recipient.
BLOOD DONATION

22. Storage and handling of blood
•Each blood donor must be tested for their healthy.
•Before donated blood is transfusion into patient,
it must be tested to ensure it is free from HIV or AIDS,
hepatitis B and C and syphilis.
•All the blood donated must be keep in cold room.

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