In some plants,the cold treatment may be replaced by the application of

The pigment involved in red-far red light interconversion is

Which two factors primarily affect the developmental phase of growth of plants?

Define/Explain: Long-day plants.

If a tree flowers thrice in a year $(October, January, \text{and } July)$ in Northern India, it is said to be

Given below are two statements.
Statement $I$: If the long dark period is interrupted by a brief flash of light,short day plants will not flower.
Statement $II$: When the long dark period is interrupted by a brief flash of light,long day plants can flower.
In the light of above statements,choose the most appropriate answer from the options given below: