Question 2
Grass covered for about three days turns yellow. Which experiment would verify this?
The right answer is the one marked above.
Cover one patch of grass with an opaque board for three days and leave a similar patch beside it uncovered. Both patches then have the same soil, water and air, and differ only in light.
It is activity 2.3 with the polythene replaced by whatever you put over the grass. The observation: the covered patch turns yellow. The conclusion: light is necessary for a plant to stay green and photosynthesise.