Angela Zeng 9C
Dilys Lam, Anita Liu, Jessica Luo, Kristine Jiahui Pan, Rachel Toh, Helen Vo
Exploring Light & Photosynthesis
To investigate whether light is a requirement for photosynthesis.
According to the theory of photosynthesis, the only way that photosynthesis in a plant can
occur is when there is carbon dioxide, water and sunlight. Without all of these three major
components nothing would happen, therefore, light is a requirement.
Methylated spirits (100ml)
Boiled water (~200mL)
2 x 250ml measuring beaker
1 x watch glass
2 x Petri dishes
1 x forceps
Protective eyeglasses and apron (see Safety Precautions)
Hot plate and boiling water: Hot plates will be switched on and therefore hot. Do not touch
the hot plate. Similarly, there will be boiling water in beakers. If you accidentally burn yourself, place
injured part under cold running tap water and ask for teacher’s assistance.
Methylated spirits: It is a flammable liquid and catches on fire easily as it is flame is not
easily visible. If you suspect that it has caught fire, cover beaker with watch glass to extinguish the
flame and ask for teacher’s assistance. Wash off immediately in contact with skin.
Iodine: Safety glasses and apron should be worn for protection over chemical spills and
iodine is to be immediately washed off on contact with skin.
Exposure of light on leaf.
The production of starch.
How will the dependent
variable be accessed?
Using iodine solution, which is the indicator for starch.
What variable have you
The amount of light accessed by the leaves.
1. Geranium leaves were labelled (A) and (B) with group members’ names using masking tape. Leaf
(A) was wrapped in aluminium foil (to stop light from penetrating the leaf). (See diagram below)