1. Chapter 2 Organisation of the organism

2. What is Cell? Cell is the basic units of life. The level of organization which is lower than cell, e.g. molecules or atoms are not considered as living, hence they need to be integrated with each other to form the most basic functional unit of life---cell. Cells are very small. Some organisms are unicellular (made up of single cell) and some larger organisms are multicellular (made up of many cells).

4. Prokaryotic Cells Example: bacterial cell No true nucleus, has nucleoid No organelle

5. Eukaryotic Cells Includes animal cell, plant cell, fungi cell, protozoa cells and algaecells. Has true nucleus. Has membrane bound organelles

7. Animal Cells Biology Cytoplasm enclosed by cell membrane Large central nucleus Has centriole Has lysosome Energy is generated by mitochondria No cell wall and chloroplast Vacuole rarely present, if present, exist in small form (commonly known as vesicles)

10. Plant Cells Biology Cytoplasm enclosed by cell membrane Has cell wall and fixed shape Has chloroplast to carry out photosynthesis Has a large central vacuole Nucleus at the peripheral Energy is generated in the mitochondria No centriole No lysosome, except in some carnivorous plant

12. Cell Membrane Semi-permeable membrane surrounding the cytoplasm of cell It helps to control the in and out of substances into the cell Mainly made up of cholesterol, proteins and some sugars.

13. Cell Wall Only present in plant cell, bacterial cell and fungal cell. In plant cell, the cell wall is made up of cellulose. Cell wall is fully permeable and it confers structural support and rigidity to the plant cell which allow the plant cell to be in the fixed shape form.

14. Cytoplasm Fluid that fill the cell and allow the organelles to float Clear thick jelly-like fluid which mainly made up of water Allow biochemical reactions to take place within the cell.

15. Organelles Organized or specialized membrane bounded structures within a living cell. Only found in eukaryotic cells Cytoplasm, cell membrane and cell wall are not organelle.

17. Nucleus Only present in eukaryotic cell and most cell contains only one nucleus Control all the activities of the cell, e.g. cell division and enzyme production. Stored the genetics materials (DNA) in the form of chromosome

18. Mitochondria Made up of double membrane structure. Provide energy to the cell (in the form of ATP) through aerobic respiration Has its own DNA Cell with high metabolisms require high amount of mitochondria to supply them high amount of energy. Animal cell with abundant of mitochondria can be found in sperm cell or muscle cell. Plant cell with abundant of mitochondria is known as meristematic cell and they are very active in cell division and development.

19. Chloroplast Made up double membrane structure Site for photosynthesis to take place Only present in plant cell Has its own DNA Cells that has abundant of chloroplast are known as mesophyll cell and they can be found in the leaves.

20. Endoplasmic Reticulum (ER) Composed of two types, the rough ER and the smooth ER. Rough ER allowed ribosome to attached and this makes them look rough.

21. Ribosome Site for protein synthesis Can be free floating in the cytoplasm or attached to the rough endoplasmic reticulum Made of 2 subunits or rRNA

22. Vacuole Contains cell sap Stored sugars or salts and sometime the toxic and waste materials. Helps to maintain the cell turgidity and thus makes the plant cell firm. Helps to remove excess waste or toxic materials from plant cell.

24. Specialized Animal Cells Ciliated Cells – movement of mucus in the trachea and bronchi

25. Specialized Animal Cells Nerve cells- conduction of impulses Red Blood Cells – transport of oxygen Sperm And Egg Cells – reproduction

27. Specialized plant cells Root hair cells-maximize the absorption of water and mineral ions from the soil. Xylem vessel- conduction and support. to transport water and mineral ions as well as to provide support for the plant to stay firm. Palisade mesophyll- maximize light absorption for photosynthesis

28. Light Microscope Most cells cannot be seen with naked eyes. They can only be visible under the microscope. Light microscope is one of the microscope that is commonly used in the laboratory. They are made up of 2 lens, the eyepiece lens and the objective lens. Hence, the total magnification of the light microscope is the product of the magnification for both lenses.

30. Test Yourself 1.Define cell. 2.Describe the function(s) of the following organelle: I.Plasma membrane II.Nucleus III.Chloroplast IV.Mitochondria V.Ribosome VI.Endoplasmic Reticulum VII.Vacuole 3.Differentiate animal cell and plant cell.

32. Tissues When many cells with similar structures are grouped together to perform similar functions, they form tissues. The study of tissues is known as Histology

34. Organs The structure which made up of a group of tissues, working together to perform specific functions is known as organ.

35. Organ System A group of organs with related functions, working together to perform some particular body functions is known as organ system.