Question

What is the site of perception of photoperiod necessary for the induction of flowering in plants?
A.Lateral buds
B.Pulvinus
C.Shoot apex
D.Leaves

Answer 1

Hint:The leaves perceive the photoperiod due to which the florigen is synthesized in the leaves and sent to the shoot apical meristem.
This results in the conversion of the shoot apical meristem with the floral meristem.

Complete answer:
The developmental responses of the plants to the relative lengths of the light and the dark periods are called photoperiodism.
Further, they have classified as three groups according to the photoperiods: the short-day plants, the long-day plants, and the day-neutral plants.
During the process of flowering, the photoperiodic stimulus is perceived by the leaves of the plants, and as a result of this, a floral hormone is produced in the leaves which are then Translocated to the apical tip, subsequently causing the initiation of floral primordial.
Therefore, the correct answer is option D.

Additional information:
In many flowering plants that are the angiosperms use a photoreceptor protein, such as the phytochrome or the cryptochrome, to sense the seasonal changes in night length, or the photoperiod, which they take as the signals to the flower.
The photoperiodism is the plant’s response to the seasonal changes.
It is the effect in which the plant wants to grow when it is either hot or cold.
The axillary bud or the lateral bud is an embryonic or the organogenic shoot located in the axil of a leaf. Each of the buds has the potential to form shoots and maybe specialized in producing either the vegetative shoots or the reproductive shoots.
The pulvinus is an enlarged section at the base of a leafstalk in some of the plants, which is subject to changes of rigidity leading to the movements of the leaf or the leaflet.
The shoot apex is the growing tip of the plant shoot and has a crucial role in the morphogenesis.

Note:The photoperiod affects reproduction in the seasonal breeders, both in plants and in the animals.
In the animals, photoperiod affects the seasonal breeder through the changes in the melatonin secretion by the pineal gland.
The reproductive axis is controlled by the melatonin which is secreted at night only and therefore relays day length to the body.