Question

PRACTICAL INVESTIGATION
Test whether starch is produced during photosynthesis
Methodology
Conduct the investigation on a green leaf that has been exposed to sunlight for a few
hours.
Place the leaf in a beaker of boiling water for 10 to 30 seconds. This will soften the leal
and kill the cells as it stops metabolism. It also makes the cell permeable to alcohol and
iodine solution.
Place the leaf in a test tube with ethanol (alcohol).
Let the test tube stand in a beaker of boiling water (water bath) for about 10 minutes.
Extinguish the Bunsen burner for safety reasons. Alcohol is highly flammable and shoul
not be heated over an open flame.
• Chlorophyll is soluble in alcohol and will be extracted from the leaf. The leaf will tur
white and become brittle.
Remove the brittle leaf (it will crumble easily) from the alcohol and rinse it in water
sofien it.
Spread the leaf on a porcelain tile and pour drops of diluted iodine solution onto it.
Now prepare the practical report with the following:
Aim
Apparatus
Methodology
Results
Discussion
Conclusion
TOTAL (30 MARKS
21 Page​

Answer 1

two inclined planes
It is made up of two inclined planes to form a sharp edge which are used to split things.