Tuesday, April 21, 2009

[Biology Form 4] Animal Cell & Plant Cell

The cell is the basic unit of all organism. It is made up of a cell membrane that encloses the cytoplasm.

Contained within the cytoplasm are not only the
nucleus but also organelles, whose specific functions help the cell perform a range of activities.

While plant and animal cells are similar, the plant cell has, in addition to the cell membrane, another boundary that separates it from its external environment. This is called the
cell wall.

As most plant cells carry out photosynthesis - the synthesis of organic substances - they contain

In plant cells,
vacuoles also tend to be larger in size and smaller in number than those found in animal cells.

Onion Skin Cell

Cheek Squamous Epithelial Cells

Typical Plant Cell

Typical Animal Cell

In the laboratory, you have learned how to prepare a microscope slide of human cheek cells as well as the epidermal cells of onions.

a) The differences you can observe between the two types of cells in term of the following:
  • Shape
    Onion cells have a regular shape while cheek cells have an irregular shape.

  • Presence or absence of cell wall
    Onion cells have a cell wall while cheek cells do not.

  • Presence or absence of vacuoles
    Onion cells have a large vacuole while vacuoles in cheek cells, if present, are small.
b) Can you observe chloroplasts in the epidermal cells of onions? Explain your answer.
No chloroplasts can be observed in the epidermal cells of onions because epidermal cells do not carry out photosynthesis.


  1. Cikgu, takde bahasa Melayuke kesian bahasa kita perlukan terjemahan yang banyak seluruh ilmu.

  2. bestnye..ade note kat sini..hehe

  3. Asian Science Essay Competition

    You are invited to enter the first ever Asian Science Essay Competition!

    Submission Deadline May 4, 2009

    Maximum Word Count: 2,000

    First Prize: $1,000 USD
    2nd Place: $500 USD
    3rd Place: $200 USD
    4th Place: $100 USD
    5th Place: $50 USD

    We invite you to submit a thought-provoking essay that represents your perspective on the current state of life science research in Asia. Essays should be of general interest, for example: how does science interact and influence society’s policy, culture, religion, ethics or economic development? Another interesting theme could be to discuss how new technologies advance the life sciences in Asia, and how will scientists gain access to them?

    This competition is sponsored by the Asia Life Science Council — a new social network of life scientists representing the views of biological researchers throughout Asia. All eligible entries received will be reviewed by a panel of independent science editors and judged on the creativity of your essay, its relevance to the Asian science community, and the clarity of your thoughts.

    The article you submit should be an original work, written in English and contain proper citations as appropriate. Please send us your submission in MS Word or as a plain text document and include your name, title, affiliation and contact information. Winners will be notified on May 15, 2009, and the winning entries published on the Asia Life Science Council website.

    More details can be found at:

    This is an excellent opportunity to present your opinions to an international audience of scientists, and help advance science in Asia!


    Lei Ung, M.Sc., M.B.A.
    Community Manager
    Lei_ung {at}asialifesciencecouncil.net

  4. thanx cikgu it is very useful for me

  5. this is my life saviour!!!
    thx a lot....

  6. techer,i nid ur help related 2 a F4C2 ques..cn u help me 2 describe how the size of an organism influences the function of contractile vacuole..i hope u cn help me by answering this question..tq 4 ur kind notes..

  7. thanx u cikgu cause snangkan keje saye...he3...

  8. cikgu..note ni cam baguish jek..x oleh ke sye download?

  9. wah bagus2 thank cikgu
    sebenarnya cikgu skool saya suruh bukak ni

  10. what means of biochemical reation of cell??is that means growth of the cell??=)

  11. Terbaik ah, senang nak buat nota. hehehe


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