Core Practical 6.5 - Investigating Light & Photosynthesis

Question 1

Photosynthesis:

Method:

Answer 1

• Bubble air through the water to oxygenate it for the plant’s needs, and a light
• Submerge the pondweed in a 1% sodium hydrogencarbonate solution in a darkened room.
• Trim the pondweed stem before placing it in the test tube.
• Measure gas volume collected in the syringe over 5 minutes.
• Adjust the independent variable by moving the light source and repeat step 5.
• Record results and plot a graph of oxygen production per minute against light distance.

Question 2

Photosynthesis:

Equipment:

Answer 2

• Aquatic plant
• Beaker
• Water
• Light source
• Timer

Question 3

Photosynthesis:

Variables:

Answer 3

• Dependent: Rate of photosynthesis
• Independent: Light intensity.
• Control: Temperature, plant species, water quality.