If a plant is kept in bright light all the 24 hours for a few days, the dark reaction (biosynthetic phase) will fail to occur.
Answer
False
If a plant is kept in bright light all the 24 hours for a few days, the dark reaction (biosynthetic phase) will continue to occur because the dark reaction is independent of light and it occurs simultaneously with the light dependent reaction.
If you immerse a leaf intact on the plant in ice cold water, it will continue to photosynthesise in bright sunshine.
Answer
False Ice cold water will hamper the process of photosynthesis in the immersed leaf, even if there is sufficient sunshine because the temperature is an important factor for the rate of photosynthesis.
The outside atmospheric temperature has no effect on the rate of photosynthesis.
Answer
False
The atmospheric temperature is an important external factor affecting photosynthesis. The rate of photosynthesis increases up to the temperature $35^{\circ} C$ after which the rate falls and the photosynthesis stops after $40^{\circ} C$.
Starch produced in a leaf remains stored in it for 2-3 weeks before it is used by other parts of the plant.
Answer
False Correct Statement: Starch produced in a leaf is stored temporarily in the leaf until the process of photosynthesis. At night it is converted back into soluble sugar and translocated to different part of the body either for the utilization or for the storage.