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Kaylee

Biology Design Lab - Tonicity

Hi everyone,

I'm still starting off in IB, so forgive me for being so confused lol. My biology teacher assigned a biology design lab write up which is due soon. It has to be relevant to the tonicity of a fruit or a vegetable. How do I go about this? Thanks in advance!

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Hi everyone,

I'm still starting off in IB, so forgive me for being so confused lol. My biology teacher assigned a biology design lab write up which is due soon. It has to be relevant to the tonicity of a fruit or a vegetable. How do I go about this? Thanks in advance!

Hmm I could be WAY over thinking this somehow, but what is tonicity exactly? :D

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We're not allwoed to give you answers outright but think about what affects the tonicity of a fruit. What can you use to quantitatively measure it. What kind of solutions would the fruit react to. Stuff like that. If you need anymore help feel free to ask.

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We're not allwoed to give you answers outright but think about what affects the tonicity of a fruit. What can you use to quantitatively measure it. What kind of solutions would the fruit react to. Stuff like that. If you need anymore help feel free to ask.

I don't see where this says IA in it, so we can give rather direct advice =/

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Tonicity is the measure of osmotic pressure of two solutions seperated by a membrane (inside and outside of the fruit). So two solutions that are isotonic have the same osmotic pressure, or in a simpler terms, has the same concentration of water and solute.

Check your book for the osmosis part, it gives you everything. A fruit is supposed to represent a cell and you want to see the reaction of the cell to different solutions. Just like the book/study guide says, you are altering the external solution.

There that's the maximum I could give you, there is one more thing you need to figure out which is how to alter the external solution and that is found by reading osmosis part of your study guide/ text book.

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Honestly, any help would be very much appreciated. I just don't know where to start... :/ Our teacher didn't really go over how to measure the tonicity of a fruit. I'm not sure if I'm supposed to design an experiment to measure how different substances affect the tonicity of a fruit or just the tonicity of the fruit by itself.

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No you are not expected to MEASURE tonicity, we don't even do that in med school. As far as IB is concerned, you need to know the effects of external solution tonicity on a cell (which is demonstrated by the fruit here)

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