Question

The day-neutral plant is
(a)Tobacco
(b)Tomato
(c)Wheat
(d)Oat

Answer 1

Hint: The mechanism of the flowering of plants depends upon the requirement and availability of light. In many flowering plants, a photoreceptor protein is used. This protein may be phytochrome or cryptochrome. These are used to sense seasonal changes like duration of night (nights are shorter in summer and longer in winters)

Complete answer:
Day-neutral plants: The plants which are not affected by either short or long duration of light are called day-neutral plants. These plants flower after a period of vegetative growth. These plants do not depend upon the daylight hours for their flowering. E.g. sunflower and tomato.

Additional Information: On the bases of the photoperiodic plants that can further be divided into obligate photoperiodic plants and facultative photoperiodic plants, obligate photoperiodic plants require a long or a short duration of the night before flowering. Facultative photoperiodic plants are bound to flower regardless of the length of the nights but are more likely to flower when the light is just right.
-Short day plants: These plants require short periods of light to flower. E.g. rice, tobacco, cotton.
-Long day plants: these plants require a long duration of exposure to light. E.g. lettuce, spinach, potato.
So, the correct answer is, ‘Tomato’

Note: Biologists believe that the proteins phytochrome and cryptochrome which are created by light during the daytime may be related to the circadian rhythm of the plants. Photoperiodism affects not only flowering but also the growth of stems, growth of roots, and seasonal loss of leaves.