Required Practicals - Photosynthesis

Question 1

What is the goal of the photosynthesis practical?

Answer 1

To investigate the effect of light intensity on the rate of photosynthesis using an aquatic organism like pondweed.

Question 2

What is the apparatus list for the photosynthesis practical?

Answer 2

-beaker
-filter funnel
-plasticine
-measuring cylinder
-10 cm piece of pondweed
-light source
-metre ruler
-stop watch

Question 3

What is the method for the photosynthesis practical?

Answer 3

-Put the pondweed into a beaker of water
-Cover the pondweed with an inverted filter funnel
-fill the measuring cylinder with water and gently position it
-use the ruler to position the beaker 1 metre away from the light source
-start the stop watch and:
count and record the number of bubbles released in 3 minutes.
record the volume of gas produced and collected in the measuring cylinder in the same time frame.
-record your results in a table
-move the light source so that the pondweed beaker is 80cm away
-refill the measuring cylinder with water and gently position it.
-repeat for distances of 60, 40 and 20cm.

Question 4

How does the rate of photosynthesis change with increased light intensity?

Answer 4

It increases until light is no longer a limiting factor.