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    I am very confused about their different roles in plant stems cells and root cells;

    From my knowledge , in stem cells auxins are at a higher concentration on the lighter side of stem. This causes cells on lighter side to elongate more than side with higher light intensity. This stem grow towards the light.

    What about in root cells? Is it completely the opposite?

    Firstly I have to ask what does auxins cause cells to do? Elongate only? Or to elongate AND inhibit cell growth? It's he only logical explanation to the question below;

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    If the side with the higher concentration were to elongate, surely the root would grow upwards! But this doesn't happen! So does auxins ALSO cause inhibition on cell growth on the lower side with higher concentration of auxins?!

    Help is appreciated!

    Thanks! - Jay


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    (Original post by Jaydude)
    I am very confused about their different roles in plant stems cells and root cells;

    From my knowledge , in stem cells auxins are at a higher concentration on the lighter side of stem. This causes cells on lighter side to elongate more than side with higher light intensity. This stem grow towards the light.

    What about in root cells? Is it completely the opposite?

    Firstly I have to ask what does auxins cause cells to do? Elongate only? Or to elongate AND inhibit cell growth? It's he only logical explanation to the question below;

    Name:  ImageUploadedByStudent Room1397137451.709320.jpg
Views: 101
Size:  129.1 KB

    If the side with the higher concentration were to elongate, surely the root would grow upwards! But this doesn't happen! So does auxins ALSO cause inhibition on cell growth on the lower side with higher concentration of auxins?!

    Help is appreciated!

    Thanks! - Jay


    Posted from TSR Mobile
    Ok firstly the IAA doesn't go down the light side of a shoot, it travels down the shaded side. When light shines on one side, the shaded side elongates which pushes the tip of the plant towards the light, so that the tip gets more light. This allows it to bend towards light. The light is the stimuli.

    There are many different auxins too. You have gibberellins, cytokinins etc and they all have different roles. Some deal with fruit ripening, elongation or cell division. Read here to find out more about the different ones.

    With roots, I'm not so sure about how auxins work here, but I think it's a positive geotropism, meaning that the roots move in the direction of the pull of gravity. Or they move in the direction of water (positive hydrotropism). So they will move towards a stimuli causing them to grow into the ground. Their auxins will react to those stimuli.

    Hopefully this will help you
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    Thanks, but also looking at the question, since there is a higher concentration of auxins on the lower side, they must be inhibiting the growth of cells right? (For the root to grow downwards, so that the upper side can elongate more as the cells aren't inhibited as much due to lower concentration if auxins there)

    Thanks!


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    (Original post by Jaydude)
    Thanks, but also looking at the question, since there is a higher concentration of auxins on the lower side, they must be inhibiting the growth of cells right? (For the root to grow downwards, so that the upper side can elongate more as the cells aren't inhibited as much due to lower concentration if auxins there)

    Thanks!


    Posted from TSR Mobile
    From my a level understanding I think in roots it does move to the lower side, (with more gravity) and here it inhibits elongation, like you said.
 
 
 
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