Unicellular organisms like amoebas are able to perform all living processes through specialized structures within their single cell. An amoeba feeds through phagocytosis, moves using pseudopods, exchanges gases through diffusion, regulates water and maintains homeostasis using a contractile vacuole, and reproduces through binary fission. Multicellular organisms have many cell types that work together through specialization and organization into tissues, organs and systems to carry out complex life functions.

1. BIOLOGY FORM 4
CHAPTER 2
CELL ORGANIZATION (2.2)

2. 2.2
CELL ORGANIZATION
Multicellular organisms can
feed, respire, excrete, move,
respond
to stimuli, reproduce and grow.
Unicellular organisms are
organisms with just a single cell.
So how is this organism able to
perform all the living

3. Lesson Outcomes
 Understand living process in
unicellular organism
the movement in unicellular
organism
the reproduction in unicellular organism
the feeding in unicellular organism
the exchange of materials in unicellular
organism

4. CELL ORGANIZATION
ORGANISMS
UNICELLULAR
ORGANISM
Single cell
organism
MULTICELLULAR
ORGANISM
larger organism
with more than
one cell

5. UNICELLULAR ORGANISM
 Simple organism
consists of a single
cell
 Each cell or
organism is a
complete unit of
life ~able to carry
out all living
processes

6. Amoeba sp.

7. AMOEBA

8. Living processes of
unicellular organism
~~~ Amoeba sp
Lives in freshwater lakes,
damp soil
 Enclosed in plasma
membrane
 constantly change shape
Also called protozoa

9. Feeding Locomotion
Living
processes of
amoeba sp.
Reproduction
Respiration
Excretion
Responses to
stimuli

10. Movement of Amoeba sp.
 Move by extending
temporary
pseusopodia or ‘false
foot’
 The rest of cytoplasm
flow slowly into this
extension, hence move
the organism along

11. Feeding of Amoeba sp.
 Engulf food via phagocytosis
 Holozoic organism - feed on microbes

13. PHAGOCYTOSIS

14. PHAGOCYTOSIS

15. Respiration of Amoeba sp.
O2
CO2
O2
CO2
Exchange of oxygen and carbon dioxide
occurs through the plasma membrane
through simple diffusion.

16. Excretion of Amoeba sp.
• The contractile vacuole is
involved in osmoregulation.
• Water diffuses into the cell and
fills the contractile vacuole.
• When the vacuole is filled to its
maximum size, it contracts to
expel its contents.

17. Responses to stimuli
• Amoeba sp. reacts by retreating from
adverse stimuli such as bright light and acidic
solution.
• In contrast, favourable stimuli such as
contact with food, cause it to move towards
the stimuli.
Food
Light
acids

18. Reproduction of Amoeba
sp.
 Binary fission - asexual
reproduction
 Once grown to a certain size
the nucleus divides
 Cytoplasm divides
 2 daughter cells form.
 When environment not
conducive, divides by spore
formation

19. THE LIFE OF MR. AMOEBA PROTEUS

22. 2.2 CELL ORGANISATION
MULTICELLULAR ORGANISM
 Organism - more than one cell
 Larger organisms ~Need many
different types of cells to carry out
life processes
 Achieved via cell specialisation and
cell organisation

24. SPECIALISATION OCCURS THROUGH THE PROCESS OF
DIFFERENTIATION

30. CELLULAR
ORGANISATION

31. Cell
The smallest unit of life capable of carrying out all
Tissue
Organ
System
Organism
the functions of living things
A group of cells of the same type that
perform a specific function in organism
Several types of tissue that carry out a
particular function
Several organs working together to
perform a function
All the systems make up a
multicellular organism.

32. Cell organisation
in animals

33. Some of the humans cells and their functions
Cell Function
Muscle cell
Able to contract and relax and are
involved in movement
White blood
cell
Involved in defence of the body against
diseases
Red blood
cell
Transports oxygen
Nerve cell Receives and sends out nerve impulses
Sperm Fertilises the ovum

35. Animal Tissue
There are 4 major types of tissues in animals:
1. Epithelial tissues
2. Muscle tissues
3. Connective tissues
4. Nerve tissues
MENC

36. 1. Epithelial Tissue
• Form a skin surface and
protect the tissue beneath it.
• Form a lining layer for tubes or
lines the cavities of the body.
• Protect against infection,
mechanical injuries and
dehydration.
• Undergo changes to form
glands.

37. Epithelial
Tissue

38. 2. Muscle Tissue
• Most abundant tissue in the body
Smooth muscle Skeletal muscle Cardiac muscle
• Contraction and
relaxation for
involuntary body
activities
(peristalsis
along digestive
tract)
• Voluntary
movements
• Contract and
relax to move
the bone
• Contract to
pump blood to
all parts of the
body.
• Involuntary
movements

39. Muscle Tissue

40. Skeletal Muscle

41. Cardiac Muscle

42. Smooth Muscle

43. 3. Connective tissue
• Holds the body together.
• For example, bone,
cartilage, blood,
tendons, ligament.

44. Connective tissue

45. Adipose Tissue
• Peripheral nuclei due to large fat storage droplet
• Deeper layer of skin, organ padding, yellow
marrow
• Reduces heat loss, energy storage, protection

46. Bones
For movement, support ,
protection of organs, mineral
storage

47. Blood
Transport of gases,
nutrients, waste
products.
Body defence against
infections.

48. Nerve Tissue
• Transmits and coordinates messages
around the body.

53. Discards
toxic waste
products
Produces off
spring
Breaks down
complex food into
simple substances
for easy
absorption by
body cells
Absorbs and
transports oxygen and
discards carbon
dioxide
Systems

54. Transports food
substances,
oxygen,
hormones and
others to the
entire body
Provides bodily
support and
protection to
solf internal
Defends the body
against disease
Systems
organs Produces
hormones that
control the
bodily
activities

55. Skin surface to
protects the
tissue beneath it.
Coordinates and
controls all bodily
activities related to
impulses and reactions
Helps in
movement of
the body.
Systems

58. systems organs tissues cells

59. Cell organisation in plants

60. Some of the plants cells and their functions
Cell Function
Parenchyma
cell
For support and storage
Xylem Transports water and mineral salts
Sieve tube
element
Transports organic product of
photosynthesis
Companion
cell
Regulates the metabolic activity of sieve
tube element
Epidermal cell
For protection and covering of other cells
beneath

61. Tissues of plants
Meristemic
tissue
permanent
tissue
Epidermal
tissues
Ground
tissues
Vascular
tissues
• Small cell, thin walls, large
nuklei, dense cytoplasm, no
vacuole.
• Young, actively dividing
• Form a layer to cover,
protect entire surface of
plant and reduces water
loss
• Provides support
and strengthens
the plants
• Transports
water, food and
support

62. 1. Meristematic tissues
Tip of shoot
Tip of root
Cambium
• Small cell,
• thin walls
• large nuclei
• dense cytoplasm,
• no vacuole.
• Young, actively
dividing

63. Root Apical
Meristem

64. 2. Epidermal
• Form a layer to
cover, protect
entire surface
of plant and
reduces water
loss

65. 3. Ground tissue
Parenchyma
Collenchyma
Sclerenchyma
Provides support
and strengthens the
plants

66. 4. Vascular tissue
• Xylem -Transportation of water and minerals from
the roots to shoot systems & support
• Phloem - Transportation of food that is synthesized
in leaves to whole plant.

68. Plant Systems
SHOOT SYSTEM
Bears flowers, fruits,
buds and leaves
ROOT SYSTEM
Anchors the plant,
absorbs water and
mineral, stores food.

72. Regulating internal
environment

73. The process to regulate and
maintain internal environment
- HOMEOSTASIS
Necessity:
to maintain optimal internal environment so that
cells can function optimally

74. What is internal environment?
1. Interstitial fluid
2. Blood plasma

75. Homeostasis of Body Fluids
1. intracellular fluid = within cells
= cytoplasm
2. extracellular fluid = outside cells
 intercellular fluid = tissue fluid =
interstitial fluid
 plasma = fluid portion of blood
Composition of fluids change as substances move
between compartments
 nutrients, oxygen, ions and wastes move in both
directions across capillary walls

77. HOMEOSTASIS
Factors to Maintain:
- Internal factors :
1. Physical:
• Temperature
• Blood pressure
• Osmotic pressure
2. Chemical:
• Salt
• Sugar
• pH

79. How is this (homeostasis)
controlled?
Negative Feedback
Mechanism

81. Homeostasis of Blood Glucose Level

82. Homeostasis of Body Temperature

83. Uniqueness of cells

84. Why are these cells so unique?
• They can perform their function optimally!
• Red blood cell – without nucleus – they
have a lot of spaces for hemoglobin so a
lot of oxygen can be carried.
• Bone – they have calcium

85. THE END

86. • Area of Focus: Levels of Biological Organization.
Atom Molecule Cell
Organelle
Tissue
Cell
Organ
Organ
System
Cell
Organism
Copyright © 2010 Ryan P. Murphy

87. Types of animal cell Characteristics Functions
Epithelial tissues •Consist of epithelial
cells arranged in a
continuous layer
•Cover the body
surface or line the
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
called neuron
•Found in brain and
spinal cord
•Send & receive
impulses to coordinate
the activities of the
body

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

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

90. Vascular tissue •Consists of xylem
tissues & phloem
tissues
•Transport water & mineral salts
from roots to the stems & leaves
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
parenchyma
mesophyll tissues,
collenchyma &
sclerenchyma
tissues
•Produces food by photosynthesis
& stores food produced
•Provides support & strengthens
the plant