Introduction
To day you will learn investigation skill, in life science we have investigation skill that you need to learn as a grade 8 leaner. these skill you will use until you finish grade12 or until you leave life sciences as a subject so you need to learn these skill as they will help you when doing experiment. you should be able to state the following when doing an investigation or experiment.
- state the aim of investigation
- create hypothesis
- write investigation question
- state dependent variable
- independent variable
- and controlled variable
- prove reliability of the results
- and state factors that must be kept constant in the investigation
Task
do this experiment and record the results or write down the observation repeat the investigation and answer the following question, testing the leaf for the presence of starch
iodine solution is used to test leaves for the presence of starch
- heat plant leaf in boiling water for 30 seconds , to kills the leaf stopping any reaction
- add the leaf to boiling ethanol in a water bath for a few minutes, the boiling ethanol dissolve the chlorophyll and removes the green colour from the leaf it turns white so it is easy to see the change in colour
- wash with water to rehydrate and soften the leaf and spread onto a white tile
- add iodine solution from a dropping pipette
after few minutes the parts of the leaf that contain starch turn the iodine from brown to blue/black
- based on the investigation what is the aim of the experiment ?
- create the hypothesis for this experiment
- what is the dependent variable?
- what is independent variable ?
- how to prove the reliability
Process
- STEP 1: to create the aim of the investigation
- you should consider the main reason or purpose the investigation ask yourself why the investigation was done ? then you start writing the aim as a statement.
- STEP 2: to create the hypothesis of the investigation
- hypothesis should be a testable statement that indicate the relationship or difference between two or more variables, it must be brief and clear.
- STEP 3: dependent variable is the variable that is being tested and measured in an experiment and it dependent on the independent variable
- STEP4: independent variable is the variable that stand alone is not change by other variable
- STEP5: to prove the reliability of the results you should repeat the investigation and state the observation
- https://youtu.be/0s_xZqvwm_s
Conclusion
The investigation must be due in 28/09/2022 at 16:00 please read before you start writing because this investigation skill are very important ask me if there is something that you don't understand my email is (emijongi@gmail.com)