Cell specialization in multicellular organisms allows for division of labor, where different cell types perform specific functions. Through differentiation, cells acquire specialized structures to become tissues like muscle and nerve cells. Tissues combine to form organs like the heart and lungs, and organ systems work together to carry out body functions. This organization allows multicellular organisms to perform complex life processes more efficiently than single-celled organisms.

2. LEARNING OUTCOMES
• To state the necessity for cell
specialisation in multicellular organisms
as compared to unicellular organisms
• To describe cell specialisation in
multicellular organisms
• To describe cell organisation in the
formation of tissues, organs & systems
in multicellular organisms.

3. CELL ORGANISATION
• Organisms are divided into 2 : unicellular
organisms & multicellular organisms
• Unicellular organisms :- single-cell organisms
such as Amoeba sp. & Paramecium sp.
• Each cell is able to carry out all the functions of
life independently.
• Multicellular organisms :- larger organisms
with more than one cell
• Need many different types of cells to carry out all
the different functions of life
• Each cell has to change in shape & form during
cell specialisation to become specific cells in
order to perform different functions

4. 2.2 CELL ORGANISATION
UNICELLULAR
ORGANISMS
• Simple organisms
consisting of only
one cell each
• Able to carry out all
living processes in
order to survive
• Examples : Amoeba
and Paramecium
(protozoa)

6. Membrane : respiration – Cytoplasm : clear on the
gaseous exchange by simple outside (ectoplasm) &
diffusion. CO2 & any dissolved grainy on the inside
diffuses out into the water (endoplasm)
Contractile vacuole :
water continually
enters by osmosis.
Contractile vacuole
swells up  full 
expels the water from
the cell =
osmoregulation

7. Live in water, including water in the
Amoeba sp. soil.Have no fixed shape.
Movement : form a pseudopodium
(‘false-foot’) – extension of cytoplasm.
Reproduction : Binary fission – when
it has grown to certain size, its nucleus
divides to form two daughter nuclei
then the cytoplasm divides and two
daughter Amoeba are formed. Under
adverse conditions such as during a
drought, its divides by spore formation.
Feeding : phagocytosis –
pseudopodium moves round a food
particle and takes it into its cytoplasm
where it forms a food vacuole.
Enzymes are added to digest the food.
Any waste is left behind as it moves
away.

8. Contractile vacuole :
Membrane : respiration – water continually
gaseous exchange by simple enters by osmosis.
diffusion. CO2 & any dissolved Contractile vacuole
diffuses out into the water swells up  full 
moves to the side of
the membrane 
expels the water from
the cell =
osmoregulation.
Alternate.
Cilia : tiny hairs
that cover the
whole surface
Oral groove :
leads food to gullet

9. Lives in stagnant water containing Paramecium
decaying plant material. Have fixed
shape, like a slipper. sp.
Movement : rhythmic beating of the
water by the cilia (rows of tiny hair)
propels the Paramecium along. If it
encounters to an obstacle, it stops,
backs up, turn 30o then moves off.
(Avoiding reaction)
Feeding : the cilia around the oral
groove brush the food down to the
gullet. A food vacuole formed.
Enzymes are added to digest it and
the nutrient diffuse into the food
cytoplasm. Waste is released through
a weak spot in the membrane called
the anal pore.

10. REPRODUC •Through binary fission.
T IO N •Also can reproduce sexually by
conjugation.
• Two individual come together and
exchange parts of their nuclei. They
then separate and each can later
divides to give four new cells.

11. M UL T I C E L L UL A R
OR GA NI S M

12. M UL T I C E L L UL A R
OR GA NI S M
• Organisms that have more than one
cell
• More complex than unicellular
organisms
• Need many different types of cells
to carry out their life process.
• Achieved through cell specialisation
and cell organisation.

13. Human

14. CELL SPECIALISATION
• Achieved through the process of
DIFFERENTIATION where the cells begin to
change in shape and form as they grow.
• The cell acquire special structures and
become specialised cells.
• Each type of cell performs only one
specific function. This is known as division
of labour.
• Through these, different functions in the
body can be performed at the same
time and can be carried out smoothly
and efficiently.

15. CELL
• Basic units of life in all organisms.
• The structural features of cells are
related to their functions.
• Cells undergo differentiation to
acquire special structures and
become specialised cells with
specific functions.

16. E x a m p le s o f a n im a l
c e ll
Muscle cells
Red blood cells
Sperm cells
Nerve cells

17. Examples of plant cells
Guard
cell

18. TISSUES
• A group of similar cells that work together
to perform a specific function
• Four main types of animal tissues :
epithelial tissues, nervous tissues, muscle
tissues & connective tissues.
Mnemonic (EN.MyC)
• The four main types of plant tissues :
epidermis tissue, meristem tissue,
vascular tissue & ground tissue
MNEMONIC  EM..VideoGames!

19. Types of animal Characteristics Functions
cell
Epithelial tissues •Consist of epithelial •Cover the body
cells arranged in a surface or line the
continuous layer cavities within the body
•Protect the underlying
cells from mechanical
injuries
•Absorb food and water
by diffusion
•Form secretory gland
Nervous tissues •Consist of nerve cells •Send & receive
called neuron impulses to coordinate
•Found in brain and the activities of the
spinal cord body

20. Muscle tissues •Consisting of muscle •Cause body
cells which can movement by means
contract to perform of contraction
work
•3 types : smooth
muscle, skeletal
muscle & cardiac
muscle
Connective tissues •Consist of elastic & •Join together body
non-elastic fibre structures, as well as
•Blood, adipose protect, hold and
tissues, cartilage & support the cell in the
bone. body
•Can store & transport
material

21. Types of plant Characteristic Functions
tissues
Epidermis •Consisting of one •Covers the entire surface of the
tissue layer of cells plant
•Examples : •Protect underlying tissues from
epidermis of physical damage & infection
leaves, stems & •Reduces water loss
roots •Epidermal cells of leaf
differentiate to become guard
cells while those at the root,
become root hair cells.
Meristem tissue •Consists if •Produces new cells by cell
undifferentiated division
cells which are
able to divide
•Occurs at the tip
of roots & shoots
& in the cambium
of stems & roots

22. Vascular tissue •Consists of xylem •Transport water & mineral salts
tissues & phloem from roots to the stems & leaves
tissues by xylem tissues
•Transport dissolved nutrients
such as glucose from the leaves
to the roots & stems by phloem
tissues
•Xylems tissues provide support
to the plants
Ground tissue •Consists of •Produces food by photosynthesis
parenchyma & stores food produced
mesophyll tissues, •Provides support & strengthens
collenchyma & the plant
sclerenchyma
tissues

23. ORGANS
• A group of different tissues that work
together to perform a specific function
• Examples of organs in animal: heart,
kidneys, lungs, skin & stomach.
• Examples of organs in plant : leaves,
stems, roots & flowers.
• Certain organ perform more than one
function.

26. S YS T E M S
• Several organs which work together to
carry out a specific function
• The human body has twelve different
systems
• All the system work together to form an
organism
• Flowering plant has two main systems :
root system, shoot system

27. MAJOR SYSTEMS IN HUMANS
• Integumentary • Muscular
• Circulatory • Excretory
• Endocrine • Skeletal
• Lymphatic • Respiratory
• Reproductive
• Nervous
• Digestive

32. THE INTERNAL ENVIRONMENT
OF MULTICELLULAR ORGANISM

33. THE INTERNAL ENVIRONMENT
OF MULTICELLULAR ORGANISM
• EXTERNAL ENVIRONMENT : external
conditions imposed on the organism such
as the physical and chemical factors in its
surroundings.
• INTERNAL ENVIRONMENT : the conditions
created inside the organism by its own
metabolism, its reactions to external
changes and other activities

34. • EXTRACELLULAR FLUID : the fluid that
bathing the cells, provides the medium in
which they have to live
• HOMEOSTASIS : the process to regulate the
physical & chemical factors in the internal
environment so that it is always constant &
at its optimal condition for the cells to
function efficiently (the maintenance of the
internal environment of a living organism
at a constant normal level or between
narrow limits).

35. ENVIRONMENT of
MULTICELLULAR
• A multicellular organism consists of all the
ORGANISM
different organ systems, each specialised to
carry out certain functions.
• They work together as an integrated &
coordinated unit.
• To stay alive, the cells in a multicellular organism
must remain bathed in a FLUID that offers
nutrients & carries away metabolic wastes.

36. • The combined contributions of
individual cells, organs & organ
systems help maintain the STABLE
INTERNAL ENVIRONMENT required for
individual cell survival.
• Any increase in the value of a physical
or chemical factor will trigger the
homeostatic mechanism to bring it
back to normal (negative feedback
mechanism)

37. FACTORS AFFECTING THE
INTERNAL ENVIRONMENT
• PHYSICAL FACTORS – temperature, blood
pressure & osmotic pressure
• CHEMICAL FACTORS – salt & sugar
content & pH value.

38. NEGATIVE FEEDBACK
MECHANISMS
• Body temperature
MNEMONICS  Cu, Mau Ikut Nenek Enggak?
• Blood glucose level
MNEMONIC Dahi Engkau Cantik!
• Blood pH
MNEMONIC  Roti Canai Enak
• Concentration of oxygen & carbon dioxide in the
blood
MNEMONIC  RaCuN
• Osmotic pressure of blood
MNEMONIC  ENCEk

39. BODY TEMPERATURE
• To regulates & maintains human body
temperature at 37oC.
• Body temperature rises  Thermoreceptors (NS)
detect  contol centre in hypothalamus
activates effectors (blood vessel & sweat
gland)  blood vessel dilate  near the surface
of the body increase the heat loss sweat
gland produce more sweat to low the body
temperature through evaporation  BT restored
to normal

41. Ooo…sleeping in Biology
class ek?
So stubborn la.
Let me ‘teach’ U first before
teacher become angry!!!
Waa….mama!
Help me…. I don’t
want to fall asleep
in the class
anymore!!!
I SWEAR!!!