CBSE Class 10 Answered

Water is essential to photosynthesis and so plants need a steady supply of water through their roots.

Activity to show that water is essential for photosynthesis:

Take 2 young potted plants (The plants used in both the pots should be same i.e. both should be rose or both sunflower etc.) The plants should be similar in age and growth. Provide optimum sunlight and temperature. Mark the first pot as A and the second one as B. Water pot  A regularly. Do not water pot B for 3 days.

After 3 days, measure the height of the plants in both pots. You will find that the plant in pot A is much taller than the plant in pot B. This is because photosynthesis occured normally in pot A, which received the normal supply of water. But the plant in pot B showed diminished growth due to lack of or greatly lowered rate of photosynthesis.