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My name is Poon Cheng Moh. I have been teaching biology in SMK(P) Raja Zarina, Port Klang for 24 years. I sincerely hope that this blog on SPM Biology will be useful to both teachers and students.

Tuesday, February 5, 2013

Amali Proses Sains Biology Pg 7-9


Aim : To study the structures of animal and plant cells
Discussion.
1Iodine solution stained the starch grains found in the chloroplasts and in the cytoplasm of  Hydrilla sp. leaf cells to dark blue.  Iodine solution did not  stain the epidermal cells of an onion into dark blue.
2. To stain the nucleus of the cheek cell so that it can be seen clearly.
3. The cytoplasm and the nucleus will be stained yellowish brown. There are no starch grains to be stained dark blue.
4. i)The epidermal cells of an onion have cell wall and vacuole whereas the cheek cells do not have any
ii) Chloroplasts are present in the leaf cells of  Hydrilla sp. but absent in cheek cells.
iii) The epidermal cells of an onion and the leaf cells of  Hydrilla sp.  have regular shape whereas the cheek cells have irregular shape.
Conclusion.
A cell from a green plant has regular shape, cell wall, large vacuole and starch grains.  An animal cell has irregular shape, does not have cell wall, large vacuole and starch grains. 

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