The site of perception of light for photoperiodism is:

Which of the following is required for the formation of flowers in plants?

Phytochrome is a

What do you understand by photoperiodism and vernalisation? Describe their significance.

$A$ group of plants flowered when exposed to a $12$ hour day and $12$ hour night cycle. Another group of the same plants did not flower when exposed to the same day-night cycle but with a brief light interruption during the night. What type of plants are these?

If a tree flowers three times a year (in $October$, $January$, and $July$) in North India, what can be said about it?