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21 Cards in this Set
- Front
- Back
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osmosis
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net diffusion
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water potential
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how free water molecules are to move
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turgid
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when a plant cell absorbs water and swells up, making the cytoplasm push against the cell wall.
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flaccid
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when a plant cell loses water and the cytoplasm is not pushing against the cell wall
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plasmolysed
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when a plant cell loses so much water that the cell wall splits away from the cell membrane and cytoplasm, causing gaps to appear
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how does being turgor help the plant
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all the cells in the plant push against each other which supports other parts of plant helping them photosynthesise properly. Also helps in functioning of the stomata
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osmosis experiment
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onion epidermis cells with water on one inner epidermis cell, and concentrated sucrose solution on the other. Under a microscope, the epidermis cell with water will be turgid and the epidermis cell with sucrose solution will be plasmolysed. Also chip mass experiment.
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why do plants need mineral ions
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mineral ions needed for plants to make organic compounds from products of photosynthesis
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by what processes are mineral ions taken up by
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active transport or diffusion
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by what process is water taken up from the soil
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osmosis
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where in the plant is water up taken to from the soil
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root epidermis cell
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how is the root adapted to ensure a high surface area
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roots are covered in root hair cells which are each long, thin specialised cells to take up water.
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what does the xylem transport and from where?
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water and mineral ions from the roots
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what does the phloem transport and from where?
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sucrose and amino acids from the leaves
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what controls the phloem
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companion cells
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transpiration
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loss of water through leaves
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at day what happens to the guard cells
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they become turgid and due to their banana shape, this opens the stoma - water loss
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at night what happens to the guard cells
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they become flaccid which closes the stoma, preventing water loss.
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why do plants need the stoma open at day but not at night
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at day the stoma is needed open as it allows gas exchange needed for respiration and photosynthesis. Also the transpiration stream needs to be open. Finally plants need to lose water at day to keep their leaves cool in the sun. However at night the leaves do not need to be kept cool, also photosynthesis doesn't take place at night and so water is not required.
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what do potometers measure
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uptake of water or transpiration
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what are the factors which increase the rate of transpiration
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temperature, humidity, light intensity and wind speed
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