Question

The effect of daily duration of light and dark periods on the growth and development of plants, especially flowering, is called

• A. Thermotaxism
• B. Thermotropism
• C. Phototropism
• D. Photoperiodism

Answer 1

The correct option is D Photoperiodism

Photoperiodism determines the amount of growth, dormancy and flowering. Flowering occurs in response to absorption of light by Cyt red and cytochrome farred, period of exposure to light that is, greater than or less than the critical value, accordingly the plants are termed long day plant, short day plant and day neutral plant. With the exposure to right amount of light the flower formation is stimulated by hormone florigen.

So, the correct answer is 'Photoperiodism'