Question

(a) Leaves of a healthy potted plant were coated with vaseline. Will this plant remain healthy for long ? Give reason for your answer. 

(b) What will happen to the rate of photosynthesis in a plant under the following circumstances ? 

1. cloudy day in morning but bright sunshine in the afternoon 

2. no rainfall in the area for a considerable time. 

3. gathering of dust on the leaves

Answer 1

(a) This plant will not remain healthy for long because vaseline coating closes the stomatal pores on the leaves due to which 

(i) plant will not get oxygen for respiration 

(ii) plant will not get carbon dioxide for photosynthesis, and 

(iii) plant will not get water (and minerals) due to stoppage of transpiration. 

(b) (i) Decreases in morning but increases in the afternoon 

(ii) Decreases. 

(iii) Decreases.