B1 3

Question 1

What’s the equation for photosynthesis?

Answer 1

6CO2 + 6H2O

= C6H12O6 + 602

Question 2

What are the two stages of photosynthesis?

Answer 2

1) light dependent- energy transferred from light splits water molecules into O gas and hydrogen ions
2) light independent - CO2 gas combines with hydrogen to make glucose

Question 3

How do you show light, chlorophyll and CO2 are essential for photosynthesis?

Answer 3

Testing for starch

Question 4

How do you test for starch (6 steps)?

Answer 4

1) use forceps to take leaf and put it into boiling water to kill it
2) Put leaf into boiling ethanol to kill chlorophyll
3) Wash leaf to remove ethanol and soften the leaf
4) Spread leaf onto white tile
5) Add a few drops of iodine solution
6) If there is starch, iodine will turn blue-black

Question 5

How do you prove chlorophyll is needed?

Answer 5

Place a destarched, variegated plant in sunlight

Question 6

How do you prove light is necessary for photosynthesis?

Answer 6

Cover leaf in light with black card or tinfoil

Question 7

How do you prove CO2 is needed for photosynthesis?

Answer 7

Place a destarched plant into a polythene bag and add a pot of soda lime (absorbs co2 and water vapour). Seal bag and place in sunlight

Question 8

How to you test O2 is produced?

Answer 8

Place an upturned teat tube above an aquatic plant. Put in light. Once gas is collected, perform glowing splint test

Question 9

How do you calculate rate of photosynthesis?

Answer 9

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