Plant mineral ions fact file

Question 1

what is the independent variable

Answer 1

ion solution

Question 2

how do you vary the independent variable

Answer 2

have 3 solution containing all ion solutions except one
e.g. one solution with no calcium, solution with no magnesium and solution with no nitrate ions

Question 3

what is used as a control

Answer 3

have one solution containing all of the ion solutions
one solution of just distilled water

Question 4

what is the dependant vaiable

Answer 4

height/growth of the mung bean

Question 5

how do you measure the dependant variable

Answer 5

measure the height with a ruler in mm everyday for two weeks
take photos to see any physical changes

Question 6

what organism variables should be controlled and how

Answer 6

age of the mung bean - pick beans at the same time
species of the mung bean - pick mung bean seeds from the same plant
use mung beans as seeds for each ion solution

Question 7

what environmental variables should be controlled and how

Answer 7

temperature
CO2 concentration
light intensity - keep plants under a light bank

Question 8

which procedural variables should be controlled and how

Answer 8

volume of ion solution used - use 40cm3 of ion solution for each plant

Question 9

what repeats should be carried out and how many

Answer 9

repeat each ion solution 5 times and calculate the mean

Question 10

what is the method

Answer 10

1. half fill a beaker with perlite granules - soil contains nutrients so use perlite granules to control the nutrients added to the plant
2. add 40cm3 of mineral solution to each of the 3 beakers (1- no nitrate, 2- no magnesium, 3- no calcium) - do his to investigate the effect of deficiency of each mineral ion
3. add 40cm3 of water to beaker 4 and all mineral solution to beaker 5 - so all mineral solution is the positive control and water solution is negative control
4. place a mung bean seedling into the perlite using forceps (roots pointing downwards). cover beaker with cling-film and place under a light bank - use clingfilm so light can still enter the beaker for photosynthesis
5. measure initial height/mass/colour each say for 2 weeks - in order to see the effect of the mineral ions on the mung bean
6. add the same volume of the correct solution to the beaker regularly - to ensure there is enough water for photosynthesis and access to mineral ions
7. repeat the experiment 5 times for each solution - to calculate the mean so results are valid