Question

Choose the correct answer from the alternatives given.
The phytochrome system helps to entrain the biological dock by indicating to a plant that light is present when:

• A. Pr is rapidly converted to Pfr
• B. Pfr is slowly converted to Pr
• C. Pr and Pfr are equal in concentration
• D. red light is absorbed by Pfr

Answer 1

The correct option is A Pr is rapidly converted to Pfr

The biological clock is the seasonal or physiological activities of the plant which changes according to time, season etc. When the light is present at the time of the night, the phytochrome system sends the signal to the biological clock which results in the activation of phytochromes thus converting Pr (Inactive form) to Off (active form). This results in the flowering of plants.

So, the correct option is 'Pr is rapidly converted to Pfr'.