B8 - Photosynthesis

Question 1

B8 - What is the word and symbol equation for photosynthesis?

Answer 1

Carbon dioxide + water → glucose + oxygen

6CO2 + 6H20 → C6H12O6 + 6O2

Question 2

B8 - Plan an experiment to investigate the effect of light intensity on photosynthesis.

Answer 2

1. Place a piece of pondweed in a test tube 10cm away from the light source.
2. Fill the boiling tube with the sodium hydrogen carbonate solution.
3. Put the piece of pondweed into the boiling tube with the cut end at the top. Gently push the pondweed down with the glass rod.
4. Leave the boiling tube for 5 minutes.
5. Start the stopwatch and count the number of bubbles produced in one minute.
6. Record the results in your results table.
7. Repeat the count twice more. Then use the data to calculate the mean number of bubbles per minute.
8. Repeat steps 5‒7 with the test tube rack and boiling tube at distances of 20 cm, 30 cm and 40 cm from the light source.

Question 3

B8 - What do plants use glucose for?

Answer 3

They store it as starch

They use it in respiration

They use it for growth and repair

They use it to make fats and oils