Question

Assertion: Shoot apices tend to modify themselves into flowering apices before flowering. Reason: Shoot apices can’t perceive photoperiods.

• A. Both assertion and reason are correct and the reason is the correct explanation to the assertion
• B. Both assertion and reason are correct but the reason is an incorrect explanation to the assertion
• C. Only assertion is correct
• D. Both are incorrect statements

Answer 1

The correct option is B Both assertion and reason are correct but the reason is an incorrect explanation to the assertion

Photoperiodic stimulation or photoperiodism is defined as the response shown by an organism to the lengths of day and night. It has been observed that a lot of plants need periodic exposure to light to induce flowering. It is the shoot apices of plants that modify themselves to flowering apices just before flowering. Hence, the assertion is correct.
However, these shoot apices do not perceive photoperiods by themselves. It is the leaves that perceive photoperiods. Hence, the reason is a correct statement but it is not the correct explanation to the given assertion.
It is believed that a hormone is responsible for flowering. This hormone is transported from leaves to the shoot apices once the plant is exposed to an adequate inductive photoperiod. That is when the shoot apices turn into flowering apices.