The name 'phytochrome' was given by

The site of perception of light in plants during photoperiodism is:

Fill in the blanks:
$(1)$ ........ initiate rooting.
$(2)$ The pigment involved in photo-perception in flowering plants is ........

One set of a plant was grown at $12$ hours day and $12$ hours night period cycles and it flowered,while in the other set,the night phase was interrupted by a flash of light and it did not produce flowers. Under which one of the following categories will you place this plant?

'Both a short day plant and a long day plant can flower simultaneously in a given place'. Explain.

Vernalization stimulates flowering in