The pigment involved in red-far red light interconversion is

Differentiate between Photoperiodism and Vernalization.

$A$ group of plants shows flowering in a $12$ hour day and $12$ hour night cycle. When the night phase of another group of the same plants is interrupted by a brief flash of light, flowering does not occur. In which of the following groups would you place these plants?

Some plants like sugarbeet and cabbage require low temperature for flowering. This phenomenon is called:

$A$ change from vegetative to reproductive phase in plants occurs in response to

Phytochrome is sensitive to