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    How's alveoli specialised to maximise diffusion?
    How's villi specialised to maximise diffusion?
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    (Original post by Abihun04)
    Preservation
    Replacement by minerals
    Casts and impressions (clay cast)
    Fantastic!
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    (Original post by Abihun04)
    Guard cells open and close the stomata, depending on the humidity and co2 levels outside the leaf. The palisade leaf cells have air spaces to maximise the gas exchange of oxygen and carbon dioxide!!

    What is an allele?
    It's the spongy mesophyll layer that has the air spaces
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    (Original post by siobhanx13)
    How's alveoli specialised to maximise diffusion?
    How's villi specialised to maximise diffusion?
    Alveoli have moist lining, thin cell membranes and close to the good blood supply andlarge surface area
    Villi have a large surface area and lots of them (making an even bigger surface area)
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    (Original post by nerdyminion)
    It's the spongy mesophyll layer that has the air spaces
    That's the one 👌🏻
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    (Original post by siobhanx13)
    How's alveoli specialised to maximise diffusion?
    How's villi specialised to maximise diffusion?
    Alveoli :
    Have a large surface area
    Thin walls (decreases distance over which diffusion occurs)
    Good blood supply
    A moist lining for dissolving gases.

    Villi:
    Increases the surface area of small intestine
    Single layer of cells (decreases distance over which diffusion occurs)
    A good blood supply which maximises absorption into the blood

    Posted from TSR Mobile
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    (Original post by ihatehannah)
    what are xylem and pholem tissues made from.
    Xylem is made from dead cells stacked on top of each other, and phloem is made from living cells stacked on top of each other. The cells in both of these tissues form tubes.
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    How does the kidneys get rid of any products that are not useful? (4)
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    (Original post by nerdyminion)
    Xylem is made from dead cells stacked on top of each other, and phloem is made from living cells stacked on top of each other. The cells in both of these tissues form tubes.
    Ask a question then...........I guess I shall go:

    Name 4 things that Animals use Proteins for.
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    (Original post by rlb2000)
    How does the kidneys get rid of any products that are not useful? (4)
    Ultrafiltration: all the waste rosiest are not filtered back into the blood. The pass through the bowmans capsule and into the nephron. The nephron filters all the sugars, some water and mineral ions (through active transport) and leaves the waste products behind, like urea. Urea gets sent towards the bladder where it's stored before removed in urine
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    (Original post by Bulletzone)
    Ask a question then...........I guess I shall go:

    Name 4 things that Animals use Proteins for.
    Except from proteins are used for growth and development so they build things i have no idea... Help?
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    (Original post by Abihun04)
    Ultrafiltration: all the waste rosiest are not filtered back into the blood. The pass through the bowmans capsule and into the nephron. The nephron filters all the sugars, some water and mineral ions (through active transport) and leaves the waste products behind, like urea. Urea gets sent towards the bladder where it's stored before removed in urine
    Great answer! probably will copy that one
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    Proteins are used as structural components of tissues, catalysts like enzymes, antibodies and hormones such as insulin and glucagon.
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    Explain how blood is circulated around the body. (6 marks)

    OR

    Explain why Arteries are thicker than Veins. (hint: blood pressure)
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    (Original post by Wahhaba)
    Explain how blood is circulated around the body. (6 marks)

    OR

    Explain why Arteries are thicker than Veins. (hint: blood pressure)
    The Arteries carry oxgenated blood away from the heart with high blood pressure, thus they have thick walls to withstand the pressure; Veins carry deoxygenated blood at low pressure.
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    give 3 possible effects on an increase of carbon dioxide in the atmosphere
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    (Original post by rlb2000)
    Great answer! probably will copy that one
    Sorry about the bad spellings and typos, typing fast
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    What pH does pepsin usually work in?
    • Thread Starter
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    (Original post by siobhanx13)
    I think so! We had an amazing teacher last year, so that helped a lot. And I'm sure you'll still do really well because you seam to care and have therefore put in a lot of effort!
    I hope so :P Good luck for tomorrow!!
    • Thread Starter
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    (Original post by studentshavefun)
    What pH does pepsin usually work in?
    pH 2?

    What is mitosis and how does it work? (4 marks)
 
 
 
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