lesson 17 required practical 3 effects of osmosis on plant tissue Flashcards
which plant can we use to investigate the effects of osmosis on plant tissue
potato (usually used)
beetroot
parsnip
first we do what with the potato
and why
peel it
because the potato skin can affect osmosis
then what do we do after peeling the potato
use a cork borer to produce three cylinders of potato
using a cork borer does what to the cylinders
makes them all the same diameter
after using the cork borer what do we do
use a scalpel to trim the cylinders to the same length
(around 3cm)
after using the scalpel, what do we do
measure the length of each cylinder using a ruler and the mass of each cylinder using a balance
one measuring the length of mass of the cylinders, what do we do
place each cylinder into a test tube
what do we add into the first test tube
add 10cm^3 of a 0.5 molar sugar solution
what do we add into the second test tube
add 10cm^3 of 0.25 molar sugar solution
what do we add to the third test tube
10cm^3 of distilled water
why do we use distilled water on the third test tube rather than tap water
because distilled water contains no dissolved substances and dissolved substances could affect the rate of osmosis
once the test tubes are finished what do we do
leave the potato cylinders overnight to allow osmosis to take place
once we have left the potato cylinders to allow osmosis to take place overnight then what occurs
we remove the potato cylinders and gently roll them on paper towel to remove any surface moisture
why do we not press on the cylinders to remove surface moisture
as we want to remove surface water, not forced water out of the cells
after we have allowed surface moisture to remove out of the cylinders, then what
measure the length and the mass of the cylinders again
