suap Posted February 11, 2004 Share Posted February 11, 2004 so ive been on the internet looking for the answer but got nothing can any of u smart people on here help out? Quote Link to comment Share on other sites More sharing options...
test pattern Posted February 11, 2004 Share Posted February 11, 2004 they don't? Quote Link to comment Share on other sites More sharing options...
Guest imported_El Mamerro Posted February 11, 2004 Share Posted February 11, 2004 Do they need them? They don't receive any sunlight underground... Quote Link to comment Share on other sites More sharing options...
26SidedCube Posted February 11, 2004 Share Posted February 11, 2004 CHLOROPLASTS IN ONION ROOT CELLS http://images.encarta.msn.com/xrefmedia/sharemed/targets/images/pho/t013/T013558A.jpg'> 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. 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. Quote Link to comment Share on other sites More sharing options...
suap Posted February 11, 2004 Author Share Posted February 11, 2004 i just need a 1 sentance answer for a take home test how can i simplfy itt 26cube? thanks for the help Quote Link to comment Share on other sites More sharing options...
Devilush Posted February 11, 2004 Share Posted February 11, 2004 wait....where's are2!!! ;) Quote Link to comment Share on other sites More sharing options...
test pattern Posted February 11, 2004 Share Posted February 11, 2004 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. Quote Link to comment Share on other sites More sharing options...
test pattern Posted February 11, 2004 Share Posted February 11, 2004 It is inefficiant for onions to develop them due to their habitat. Quote Link to comment Share on other sites More sharing options...
GnomeToys Posted February 11, 2004 Share Posted February 11, 2004 They're root cells. Onions grow their leaves above ground, and have their chloroplasts there. Quote Link to comment Share on other sites More sharing options...
BIGBLUE Posted February 11, 2004 Share Posted February 11, 2004 Originally posted by GnomeToys They're root cells. Onions grow their leaves above ground, and have their chloroplasts there. Quote Link to comment Share on other sites More sharing options...
Guest imported_Tesseract Posted February 11, 2004 Share Posted February 11, 2004 Originally posted by suap i just need a 1 sentance answer for a take home test how can i simplfy itt 26cube? thanks for the help you want to him to whipe your ass maybe? Quote Link to comment Share on other sites More sharing options...
!@#$% Posted February 11, 2004 Share Posted February 11, 2004 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. Quote Link to comment Share on other sites More sharing options...
suap Posted February 11, 2004 Author Share Posted February 11, 2004 thanks for all the help god bless you all Quote Link to comment Share on other sites More sharing options...
26SidedCube Posted February 11, 2004 Share Posted February 11, 2004 Originally posted by Tesseract you want to him to whipe your ass maybe? Good to know someone's playing shortstop while I'm out in left field. Handled perfect. Quote Link to comment Share on other sites More sharing options...
Guest imported_Tesseract Posted February 12, 2004 Share Posted February 12, 2004 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?! Quote Link to comment Share on other sites More sharing options...
Al Green Posted February 12, 2004 Share Posted February 12, 2004 but.. they will sprout a green leafish thing.. once it gets above ground.. soo .. is the mystery completely solved or what. Quote Link to comment Share on other sites More sharing options...
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