I think that the shape of the graph with the end results will have a steady rising. I will not use concentrations that are too high because this will inhibit the plants growth and eventually will kill the plant. Before the auxin inhibits growth, it stops the development of the lateral bud. This will make the plant bush out and produce more branches and fruit before it dies. This is not what I want so I will use a relatively weak concentration with the highest being 0.001% as given.
The overall shape of the final results will be a positive steady straight line.
Plan
Method:
I will use 5 different concentrations for the cuttings so that I will be able to get a more accurate line of best fit. The 5 concentrations I will use will be 0.001%, 0.0005%, 0.00025%, 0.000125%, and 0%
Each concentration will be used on three separate occasions just in case I come over an anomalous result (a result that doesn’t follow the pattern). In total, I will take 15 cuttings from a willow plant.
Each cutting that is going to be taken must be cut under the lateral bud so that it is possible that the cuttings can form roots if they are left in water or auxin solution. The cutting must be dipped into rooting powder and planted in a test tube. A measured amount of 5cm3 of the water or auxin solution will be put at the bottom of the test tube and will be given an extra 5cm3 every day at the same time of day. For the results, I will count the number of roots that have formed.
Variables:
The input variable is the concentration of the solution. The outcome variable will be the number of roots that have formed. The input variable will be measured by the percentage of the auxin/water solution. The percentage will be accurate because I will add a certain amount of water to the original 0.001% solution. Each percentage will be half the concentration of the next strongest solution.
The outcome variable will be measured by the number of roots that are larger than 1mm in length.
The input variable has a direct effect on the outcome variable because auxin controls how much cells grow and in which direction how quickly they reproduce. Auxin, in roots, controls the roots to grow downwards by the act of gravity (gravitropism).
The controlled variables will be:
- To keep the amount and intensity of light the same for all 15 cuttings.
- To keep the temperature the same for all 15 cuttings.
- To keep the amount of plant at the beginning the same for all 15 cuttings.
- To get all 15 cuttings from the same plant.
- To keep the amount of water vapour in the air the same for all 15 cuttings.
- To keep the amount of water/auxin solution the same for all 15 cuttings.
- To make sure that all the results are recorded at the same time.
Safety Aspects:
I will ensure that I will be wearing safety goggles as will anybody around me watching me preparing and carrying out my experiment. I will also ensure that anybody with long hair will tie it up so that it is off his or her face. Also I will make sure every thing is out of the way so that nobody will trip over any thing like stools, bags etc.
Specimen Results Table:
This is the specimen results table that I have thought of for this experiment:
By Andrew Riddell 5P