2. Biology

3. CELL CELL The basic unit of structure and function in living organisms. The basic unit of structure and function in living organisms. Extremely small Extremely small can be seen properly only when magnified and viewed through microscope. can be seen properly only when magnified and viewed through microscope.

4. CELL CELL Your body has about 50 billion cells; some microscopic organisms only have one cell, e.g. amoeba. Your body has about 50 billion cells; some microscopic organisms only have one cell, e.g. amoeba.

5. The structure of a typical plant cell cell wall cell membrane vacuole cytoplasm nucleus chloroplast Non-living granules

6. Cell Wall Found in plant cells only. Found in plant cells only. Made of cellulose fibre. Made of cellulose fibre. Freely permeable. Freely permeable. Functions : a/ To protect and support the enclosed protoplasm. a/ To protect and support the enclosed protoplasm. b/ To resist the entry of excess water into the cell. b/ To resist the entry of excess water into the cell.

7. Cell membrane / Plasma membrane All cells are surrounded by cell membrane. All cells are surrounded by cell membrane. It is very thin. It is very thin. It is selectively permeable. It is selectively permeable. Function: Function: To control the passage of materials in and out of the cell. To control the passage of materials in and out of the cell.

8. Cytoplasm A clear, jelly like substance enclosed by the cell membrane. A clear, jelly like substance enclosed by the cell membrane. It consists of an aqueous solution with proteins. It consists of an aqueous solution with proteins. Function: Function: a/ A medium for chemical reactions to take place. a/ A medium for chemical reactions to take place. b/ To hold the organelles and granules. b/ To hold the organelles and granules.

9. Organelles Chloroplasts Present in green plant cells Present in green plant cells Contains the green pigment chlorophyll Contains the green pigment chlorophyll Function: Function: The site of photosynthesis. The site of photosynthesis.

10. Organelles Mitochondria Present in all living cells. Present in all living cells. Appear as rod-shaped or cylindrical organelles. Appear as rod-shaped or cylindrical organelles. Cellular respiration takes place there and food is oxidized to release energy. Cellular respiration takes place there and food is oxidized to release energy. Also known as the ‘Power House’. Also known as the ‘Power House’. Function: Function: Site of respiration. Site of respiration.

11. Granules Crystals of insoluble waste. Crystals of insoluble waste. Starch granules in the cytoplasm as food reserve in plant cells. Starch granules in the cytoplasm as food reserve in plant cells.

12. Vacuole Fluid-filled cavities bounded by a membrane called tonoplast. Fluid-filled cavities bounded by a membrane called tonoplast. Contains a solution of sugars, protein and mineral salts called cell sap. Contains a solution of sugars, protein and mineral salts called cell sap. The vacuoles of animal cells are usually very small. The vacuoles of animal cells are usually very small. vacuole

13. Nucleus Contains genes (carry the genetic information). Contains genes (carry the genetic information). Genes are made up of DNA and they are located on the chromatin/chromosomes. Genes are made up of DNA and they are located on the chromatin/chromosomes.

14. Nucleus Function: Function: a/ controls the activities a/ controls the activities of the cell. of the cell. b/ transmits genetic b/ transmits genetic information to the information to the next generation. next generation.

15. Basic structure of animal cell mitochondrion nucleus nucleolus nuclear membrane cytoplasm vacuole cell membrane

16. Animal Cells Animal cells do not have cell wall and chloroplast. Animal cells do not have cell wall and chloroplast. The vacuole in animal cells are usually small. The vacuole in animal cells are usually small. Non-living granules are usually glycogen or oil droplets. Non-living granules are usually glycogen or oil droplets. There is a greater variety of animal cells than the plant cells. There is a greater variety of animal cells than the plant cells.

17. Similarities between animal and plant cells Both have: nucleuscytoplasm mitochondrionchloroplast cell wallcell membrane

18. Differences in Animal and Plant Cells

20. Can you distinguish plant cells and animal cells from the following pictures? Plant cellsAnimal cells

21. Can you distinguish plant cells and animal cells from the following pictures? Animal cellsPlant cells

22. WEB SITES http://library.thinkquest.org/3564/ http://www.kapili.com/biology4kids/cell http://personal.tmlp.com/Jimr57/tour/cell/