Chapter 2 >>> Cell as a Unit of life

Below are summary of Form 1 Chapter 2 :

• Cell is a basic unit of living things.
• Each cell can function and survive on its own. Cells can perform life processes such as digestion, respiration, excretion, reproduction, growth, and response to stimuli.
• Animal cell do not have definite  shapes because there are no cell wall. The cell do not have chloroplasts to help manufacture food. The number of vacuoles in animal cells is very small and sometimes none at all.  
• Plant cell have definite shape because the cell walls are made up of cellulose. The cell can also manufacture their own food because the chloroplasts have chlorophyll. The vacuoles of plant cell are big and fill with cell sap.

Plant cell

Animal Cell

• Unicellular organisms are  organisms made up of one cell only (single cell). Examples : Amoeba, Euglena and  yeast.



Euglena

Amoeba

• Multicellular organisms are organsms with many cells. Multicellular organisms are more complex than unicellular organisms. Examples : Hydra, Spirogyra, human beings.



Human Being

Spirogyra





• Both unicellular and multicellular organisms can perform similar life process.
• Organisation of cell in the human body involves the following stages:

                    Cell =>> Tissue =>> Organ =>> System =>> Organism

For more information , students can go to this page and have a view on Chapter 2 : http://www.scribd.com/doc/14616958/Science-Form-1-Chapter-2

Thank you ^^