Welcome!

By registering with us, you'll be able to discuss, share and private message with other members of our community.

  1. Welcome to the 12ozProphet Forum...
    You are currently logged out and viewing our forum as a guest which only allows limited access to our discussions, photos and other forum features. If you are a 12ozProphet Member please login to get the full experience.

    If you are not a 12ozProphet Member, please take a moment to register to gain full access to our website and all of its features. As a 12ozProphet Member you will be able to post comments, start discussions, communicate privately with other members and access members-only content. Registration is fast, simple and free, so join today and be a part of the largest and longest running Graffiti, Art, Style & Culture forum online.

    Please note, if you are a 12ozProphet Member and are locked out of your account, you can recover your account using the 'lost password' link in the login form. If you no longer have access to the email you registered with, please email us at info@12ozprophet.com and we'll help you recover your account. Welcome to the 12ozProphet Forum (and don't forget to follow @12ozprophet in Instagram)!

Why do onion cells have no green dots (chloroplasts) in them?

Discussion in 'Channel Zero' started by suap, Feb 11, 2004.

  1. suap

    suap Banned

    Joined: Jul 30, 2002 Messages: 75 Likes Received: 0
    so ive been on the internet looking for the answer but got nothing
    can any of u smart people on here help out?
     
  2. test pattern

    test pattern Elite Member

    Joined: Jan 21, 2002 Messages: 3,975 Likes Received: 0
  3. Do they need them? They don't receive any sunlight underground...
     
  4. 26SidedCube

    26SidedCube Veteran Member

    Joined: Mar 18, 2003 Messages: 6,590 Likes Received: 9
    CHLOROPLASTS IN ONION ROOT CELLS

    http://images.encarta.msn.com/xrefmedia/sharemed/targets/images/pho/t013/T013558A.jpg'>

    [b]Chloroplasts are minute, green, spherical structures that are essential to the process of photosynthesis. The chlorophyll molecule, a very complex organic molecule composed primarily of magnesium, carbon, and hydrogen, regulates the absorption of the red, violet, and blue portions of the visible light spectrum.[/b]

    Mammero hit the nail on the cudicle:

    No, this has nothing to do with dead cells. In truth the practical answer
    to this is that they don't need chloroplasts. Think of where an onion
    lives and how much light it normally receives. Chloroplasts only function
    in the presence of light. Because it costs energy to develop chloroplasts,
    it is not useful for the plant to put develop them if they won't function.
    However accurate, this answer is a little simplified compared to what
    really happens.

    Chloroplasts are only one type of plastid, along with chromoplasts (causing
    the red color of peppers and tomatoes) and amyloplasts (storing starch in
    potatoes and corn). None of these plastids can be assembled from raw
    materials within the cell of a plant. Rather they all develop from another
    type of plastid called a proplastid. Proplastids are small and clear.
    They divide at the same time the cells divide, so every cell in a plant has
    proplastids. However, they are difficult to see in most plants because of
    their size.

    One piece of evidence that the proplastids exist in onion cells is easily
    seen. Leave an onion exposed to light for several days or weeks. It will
    begin to grow new green leaves. Also, some of the outer layers of the bulb
    (actually leaves, too), will begin to green up, as their proplastids
    develop into chloroplasts.

    According to Eames and MacDaniels (1925, p 12)
    Plastids may be found in all living cells of a plant, and probably are
    present in every cell in the early stages of development. Later they
    become restricted to certain cells, and are abundant only in those which
    have specialized functions, such as photosynthesis, storage, and color
    manifestation. Plastids do not occur in the fungia, bacteria, …
    …Plastids multiply freely by division, and in this way the large numbers
    present in some cells are in part secured. Plastids are present in the
    very young meristematic dells where they are very minute, the smallest
    being at the limit of [light, not electron] microscopic visibility.

    References:

    Eames, A.J. and L.H.MacDaniels. 1925. An Introduction to Plant Anatomy.
    McGraw-Hill Book Company, Inc:NY.

    Esau, K. 1953. Plant Anatomy. John Wiley And Sons, Inc:NY.

    Esau, K. 1977. Anatomy of Seed Plants, 2nd ed. John Wiley and Sons,
    Inc:NY.
     
  5. suap

    suap Banned

    Joined: Jul 30, 2002 Messages: 75 Likes Received: 0
    i just need a 1 sentance answer for a take home test

    how can i simplfy itt 26cube?


    thanks for the help
     
  6. Devilush

    Devilush 12oz Legend

    Joined: Feb 1, 2001 Messages: 17,035 Likes Received: 2
    wait....where's are2!!!

    ;)
     
  7. test pattern

    test pattern Elite Member

    Joined: Jan 21, 2002 Messages: 3,975 Likes Received: 0
    i was going to suggest what mammero said, but i'm not very confident in my mathematical or scientific answers. i don't like to trust systems.
     
  8. test pattern

    test pattern Elite Member

    Joined: Jan 21, 2002 Messages: 3,975 Likes Received: 0
    It is inefficiant for onions to develop them due to their habitat.
     
  9. GnomeToys

    GnomeToys Elite Member

    Joined: Jun 24, 2003 Messages: 2,616 Likes Received: 4
    They're root cells. Onions grow their leaves above ground, and have their chloroplasts there.
     
  10. BIGBLUE

    BIGBLUE Senior Member

    Joined: Jul 4, 2003 Messages: 1,667 Likes Received: 0
     
  11. you want to him to whipe your ass maybe?
     
  12. !@#$%

    !@#$% Moderator Crew

    Joined: Oct 1, 2002 Messages: 18,517 Likes Received: 621
    poor kid can't spell "sentence"

    so......

    "Onions are roots, and since photosynthesis is a light-dependent reaction, chloroplasts in onion cells would be unable to produce energy."

    now bend over.
     
  13. suap

    suap Banned

    Joined: Jul 30, 2002 Messages: 75 Likes Received: 0
    thanks for all the help

    god bless you all
     
  14. 26SidedCube

    26SidedCube Veteran Member

    Joined: Mar 18, 2003 Messages: 6,590 Likes Received: 9
    Good to know someone's playing shortstop
    while I'm out in left field. Handled perfect.
     
  15. haha, and after take home test was taken care off by people on the internet..lets move to the real question...


    how to make krink?!
     
Top