1. How does a cell become an organism?

2. Today, you will learn…
that cells of similar structures are organised into tissues
that several tissues may make up an organ
that organs are organised into systems
to explain the significance of division of labour

3. What are the main functions of a cell?
Let’s discuss:
What are the main functions of a cell?
What are the main functions of an organism?
Pass out one piece of track to each student *

4. Unicellular Organisms
Paramecium
Amoeba

5. Unicellular Organisms
Paramecium
Microscopic organism
Found on surface of water (eg: pond, river)
Has hair surrounding the body for movement
Has a mouth
Can/does it perform all functions it needs to stay alive?

6. Unicellular Organisms
Amoeba
Often found at bottom of ponds or under rocks
Does not move fast
No arms, legs, eyes, mouth
Eats by surrounding its prey with its body
Lives only for 2 days
Reproduce by splitting itself into 2 new amoebas *

7. How do we go from to ?

8. Multicellular Organisms
Have many different cells
Different cells perform different functions
Examples
Plants
Humans

9. Cells in a Human Examples Red blood cell (transport oxygen)
Nerve cell (have nerve fibres to transmit signals to and from the central nervous system)

10. Cells in a Plant
Examples
Root hair cell
Leaf guard cell

11. From cells to tissues Tissue
Group of similar cells that are specialized to perform a particular function
Students build a length of track at their tables *

12. Tissues in a Human Epithelial tissue
Covering or lining tissue to protect structure beneath it
Connective tissue
Joins, stores or supports all parts of an organism

13. Tissues in a Human Muscle tissue Cause movement Nerve tissue
Carry messages from one part of body to another by conducting electrical signals

14. Tissues in a Plant Epidermal tissue
Protects plant against injury and losing too much water
Vascular tissue
Transports materials within a plant

15. Tissues in a Plant Photosynthesis tissue
Carries out photosynthesis in a plant

16. From Tissues to Organs Organ
Group of specialized tissues that are gathered in a certain part of the body to perform a particular function together
Students build an oval with their tissues *

17. Organs in a Human
Examples
Skin
Lungs
Heart

18. Organs in a Plant
Examples
Leaves
Stem
Roots
Flowers

19. From Organs to Systems System
Different organs working together to perform a major function in an organism
Connect the different ovals to form a layout *

20. Main Organ Systems in a Human
Respiratory system
Digestive system
Blood circulatory system
Skeletal system
Muscular system

21. The Human Body
- An organism
CELLS
TISSUES
ORGANS
SYSTEMS
ORGANISM

22. Division of Labor
Each cell in a multicellular organism does not perform all the bodily functions.
Each type of cell specializes in performing one particular function.
Different functions in a multicellular organism can be performed at the same time by division of labour.

23. Division of Labor Division of labor
Sharing different functions in an organism among its cells, tissues, organs and systems nsures smooth running and effective working of the different parts in an organisms as well as the organism as a whole