Question

Some students investigated the effect of light intensity on the rate of photosynthesis.
They used the apparatus shown in Figure 1.

Figure 1
The students:
- placed the lamp 10 cm from the pondweed
- counted the number of bubbles of gas released from the pondweed in 1 minute
- repeated this for different distances between the lamp and the pondweed.
The lamp gives out heat as well as light.


What could the students do to make sure that heat from the lamp did not affect the rate of photosynthesis?

Answer 1

The effect of light intensity on the photosynthesis rate using an aquatic organism. The effect of light intensity on photosynthesis can be investigated in water plants. Use Cabomba or Elodea, which are sold in aquarium shops. The plants will release bubbles of oxygen – a product of photosynthesis

Answer 2

The student can do a couple of things to make sure that the heat from the lamp did not affect the rate of photosynthesis. These include:

• Using a heat screen that light can pass through easily.
• Using Light Emission Diode in the place of the bulb.
• Using low energy bulb that will generate very little to no heat.
• Adding a water bath will ensure that the heat is absorbed by the water in the bath instead of heating the water in the test tube directly.

Using any of the above will greatly minimize or totally eliminate the heat that will get to the plant and hence, will have no effect on the rate of photosynthesis.

More on the rate of photosynthesis can be found here: https://brainly.com/question/13201447