REQUIRED PRACTICAL: PHOTOSYNTHESIS

Question 1

What are you investigating in the experiment?

Answer 1

• how light intensity affects the rate of photosynthesis

Question 2

Why was sodium hydrogen carbonate added to the boiling tube?

Answer 2

• to encourage the plant to carry out photosynthesis

Question 3

What will we be measuring/counting?

Answer 3

• the number of oxygen bubbles produced by the plant in 1 minute

Question 4

How will we be changing the light intensity?

Answer 4

• we will change the distance between the light source and the pond weed

Question 5

Why is it better to use an LED light source?

Answer 5

• so the heat from the lamp does not affect the results

- if the temperature increases, this will increase the rate of photosynthesis, so two variables would be changing

Question 6

What repeats will be done?

Answer 6

• 5 in total (10cm, 20cm, 30cm, 40cm and 50cm)

Question 7

What error has been introduced in the experiment?

Answer 7

• we have assumed that all the oxygen bubbles are the same volume

Question 8

In the second style of experiment, what is done differently?

Answer 8

• the oxygen gas is collected instead of letting it escape, so that the volume can be measured