Assertion $(A)$: Vernalization is the acceleration of subsequent flowering by low-temperature treatment.
Reason $(R)$: The site of vernalization is the apical meristem.

The area of photoperception in plants is

What is the function of light in plants?

Which of the following is a short-day plant?

The relation of flowering to the lengths of light and dark periods was investigated by two experiments. In one experiment,the plants were subjected to dark periods of various lengths while the light periods were kept at $4$ hours. In the second experiment,plants were kept in dark periods of various lengths while the light periods were kept at $16$ hours. The number of flowers formed in relation to these periods is shown in the table. These results indicate that flowering:

Dark periods (hours)	Flowers formed (Light: $4$ hrs / $16$ hrs)
$8$	$0$ / $0$
$10$	$0$ / $0$
$12$	$4$ / $6$
$14$	$5$ / $7$
$16$	$5$ / $8$

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