Which chemical is associated with flowering?

Subjecting the growing of which plant to a cold treatment stimulates subsequent photoperiodic flowering response?

Which of the following is a short day plant?

Assertion: Dark period plays a more important part in flowering than the light period.
Reason: Flowering occurs in short-day plants if the dark period is interrupted by a light break.

Which of the following factors exclusively affects reproduction in seasonal breeders,both plants and animals?

Examples of plants which require vernalization is/are: