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    I am really confused about guard cells, stomata, transpiration and photosynthesis??
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    (Original post by Westsidegirl)
    I am really confused about guard cells, stomata, transpiration and photosynthesis??
    What do you not understand? There is not much to udnerstand with stomata, Guard cells.
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    Basically, I don't understand how stomata work in a plant? My textbook says that transpiration is a side effect of photosynthesis adaptations which i also dont understand? I know that the leaves have stomata to allow gas exchange to happen but how does this affect transpiration? stomata are affected by light, so when it is dark they close right? but dont they also close when there is a lack of water - but then how can photosynthesis happen?
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    Water enters the plant through roots, travels through xylem vessels moving to the leaves which has lower water potential. Stomata are pores in the leaves. guard cells control these pores. Water is needed for photosynthesis. Where does photosynthesis occur? In the leaves. What is transpiration? It's the movement of water/moisture from the roots to the underside of leaves where is changes to vapour.
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    Basically, I don't understand how stomata work in a plant? My textbook says that transpiration is a side effect of photosynthesis adaptations which i also dont understand? I know that the leaves have stomata to allow gas exchange to happen but how does this affect transpiration? stomata are affected by light, so when it is dark they close right? but dont they also close when there is a lack of water - but then how can photosynthesis happen?
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    (Original post by Westsidegirl)
    Basically, I don't understand how stomata work in a plant? My textbook says that transpiration is a side effect of photosynthesis adaptations which i also dont understand? I know that the leaves have stomata to allow gas exchange to happen but how does this affect transpiration? stomata are affected by light, so when it is dark they close right? but dont they also close when there is a lack of water - but then how can photosynthesis happen?
    Transpiration is movement of water. If transpiration rate increases, then you have more water moving to the leaves. ok? If you have more water in the leaves then the water used by photosynthesis. it turns to vapour and is released by stomata. Most water gained is released. Also photosynthesis can occur during night as there are two stages. The light dependent and light independent. The light dependent stage uses the water. The light independent does not.
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    (Original post by Westsidegirl)
    Basically, I don't understand how stomata work in a plant? My textbook says that transpiration is a side effect of photosynthesis adaptations which i also dont understand? I know that the leaves have stomata to allow gas exchange to happen but how does this affect transpiration? stomata are affected by light, so when it is dark they close right? but dont they also close when there is a lack of water - but then how can photosynthesis happen?
    If it is dark photosynthesis "wont occur" (it does but on basic terms) so close so c02 is not taken in. Problem is your failing to realise there are multiple reasons stomata will close. Just because 1 factor says it will close there are others to say it will open. You just need to know why each factor causes a particular response. In terms of what really happens will depend on many factors like temperature and humidity as well as enzymes.
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    (Original post by Konanabanana)
    Water enters the plant through roots, travels through xylem vessels moving to the leaves which has lower water potential. Stomata are pores in the leaves. guard cells control these pores. Water is needed for photosynthesis. Where does photosynthesis occur? In the leaves. What is transpiration? It's the movement of water/moisture from the roots to the underside of leaves where is changes to vapour.
    Okay, so the stomata open during the day but close during the night. but if they are closed during the night how does transpiration still occur? also if the guard cells are flaccid and not turgid due to a lack of water, the stomata will close but then how can gas exchange for photosynthesis still occur? and how is transpiration a SIDE EFFECT of photosynthesis adaptations?? also if a plant wants to conserve water, so has fewer stomata and closes during the day, but open during the night, how can photosynthesis occur during the day efficiently.
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    (Original post by Westsidegirl)
    Okay, so the stomata open during the day but close during the night. but if they are closed during the night how does transpiration still occur? also if the guard cells are flaccid and not turgid due to a lack of water, the stomata will close but then how can gas exchange for photosynthesis still occur? and how is transpiration a SIDE EFFECT of photosynthesis adaptations?? also if a plant wants to conserve water, so has fewer stomata and closes during the day, but open during the night, how can photosynthesis occur during the day efficiently.
    Like i said there are more than 1 factor that cause stomata to open and close. May depend on Light, water content, Temperature and Minerals. For Guard cells alone, if they take in water by osmosis they close stomata. Your confused by why gas exchange can't still happen? Oxygen can still diffuse through the leaf if the gradient is sufficient. If the gradient is not sufficient enough then the plant hardly needs oxygen anyways. If the oxygen has a high demand and low supply of oxygen during the night this will cause the gradient large concentration gradient and this will force oxygen into the leaf. The stomata don't close because there is a lack of water at night, its the fact the guard cells don't have sufficient positive ions e.g K+ to drive osmosis to occur. Like i said earlier, i don't think you need to learn this topic in a lot of detail you just need to know how each factor affects 1 thing. Your trying to learn everything at once and it can get confusing. Hope i helped, sorry for late reply i fell as sleep.
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    stomata are the pores at the bottom of the leaf and the guard cells control the opening and closing of the pores depending on the water level in the plant cells.
    What else do you need to know?
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    The guard cells close during the night and in the dark and instead of photosynthesis they aerboically respire, plant cells have mitochondria too!
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    (Original post by Konanabanana)
    Like i said there are more than 1 factor that cause stomata to open and close. May depend on Light, water content, Temperature and Minerals. For Guard cells alone, if they take in water by osmosis they close stomata. Your confused by why gas exchange can't still happen? Oxygen can still diffuse through the leaf if the gradient is sufficient. If the gradient is not sufficient enough then the plant hardly needs oxygen anyways. If the oxygen has a high demand and low supply of oxygen during the night this will cause the gradient large concentration gradient and this will force oxygen into the leaf. The stomata don't close because there is a lack of water at night, its the fact the guard cells don't have sufficient positive ions e.g K+ to drive osmosis to occur. Like i said earlier, i don't think you need to learn this topic in a lot of detail you just need to know how each factor affects 1 thing. Your trying to learn everything at once and it can get confusing. Hope i helped, sorry for late reply i fell as sleep.
    Thanks so much for replying, you helped a lot. i know my questions probably seem really stupid but its just my biology gcse is really soon so i just need to clear my understanding. thanks again
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    (Original post by Westsidegirl)
    Thanks so much for replying, you helped a lot. i know my questions probably seem really stupid but its just my biology gcse is really soon so i just need to clear my understanding. thanks again
    No problem, stay positive you will do well in that topic if you just learn them separately. If you need anymore help in your sciences feel free to ask i'm more than happy to help.
 
 
 

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