B1.4.2 - PHOTOSYNTHESIS EXPERIMENTS!!!!

How can you test for starch?

1. take a leaf and place it in a beaker of boiling water

2. once it has been killed, take the leaf and place it in a boiling tube of boiling ethanol to remove chlorophyl

3. wash leaf with water to sofen and remove ethanol

4. add drops of iodine

5. if starch it will turn from ORANGY- BROWN to DARK BLUE

How can you prove chlorophyl is needed for photosynthesis?

1. place destarched variegated plant in sunlight for several hours

2. then test one of its leaf for starch

How can you prove light is needed for photosynthesis?

1. take a destarched leaf and place black card on part of it

2. this means light cannot reach it

3. place leaf in sunlight for several hours then test for presence of starch

How can you prove carbon dioxide is needed for photosynthesis?

1. take destarched leaf and place in a polytene bag

2. add bag of soda lime as it absorbs carbon dioxide and water vapour

3. place in sunlight then test for starch

How can you prove oxygen is given off in photosynthesis?

1. place upturned test tube above plant such as pondweed

2. put this is sunlight for maximum photosynthesis

3. once tube is full of gas place glowing splint inside

4. if it relights oxygen is present