A man has a garden centre. He grows his plants in a glasshouse.
He does this so that he can produce large, healthy plants for safe.

Q1b) the man has to create the best growing conditions for his plants.
He cleans the windows regularly and uses a paraffin heater to keep the air warm.
The waste gas from the paraffin heater is circulated through the glasshouse.
He waters the plants with a fertiliser which contains magnesium salts.

Explain how each of these actions improves the rate of photosynthesis in his plants.

(i) keep the windows clean [1]

(ii) circulating the waste gas from the burned paraffin through the greenhouse [1]

(iii) watering the plants with a fertiliser solution containing magnesium salts [1]