Effect of Light in Photosynthesis Required Practical

Question 1

What equipment is needed?

Answer 1

Boiling tube
Pondweed (10cm)
Light source
Ruler
Test tube rack
Stopwatch
0.2% solution of NaHCO3
Glass Rod

Question 2

How can we tell if an aquatic plant is producing oxygen?

Answer 2

If there are bubbles coming from the plant

Question 3

What is an issue with counting the bubbles?

Answer 3

-Different shapes and sizes
-Can easily miscount

Question 4

What is the Independent variable?

Answer 4

Distance from the light source

Question 5

What is the dependent variable?

Answer 5

Amount of oxygen bubbles produced or photosynthesis

Question 6

What is the control variable?

Answer 6

Time for measuring amount of bubbles
Pondweed
Sodium hydrogen carbonate solution

Question 7

What is the Method?

Answer 7

1) Put boiling tube in test tube rack 10 cm away from light source
2) Fill it up with sodium hydrogen carbonate solution
3) Add pondweed
4) Leave for 5 minutes
5) Start stop watch and count number of bubbles and repeat, then calculate the mean
6) Repeat steps from different distances (10cm, 20cm, 30cm)

Question 8

What is inverse square law?

Answer 8

1
Light intensity is inversely proportional to 1 divided by distance^2