Question

Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A): Leaves produce a light receiving protein that induces flowering.
Reason (R): The Protein phytochrome present in leaves detects the duration of light and dark periods and help in flowering.
In light of the above statements, choose the correct answer from the options given below.

• A. Both (A) and (R) are true and (R) is the correct explanation of (A).
• B. Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
• C. (A) is true but (R) is false.
• D. (A) is false but (R) is true.

Hint:

Check whether each statement is true and whether the second one explains why leaves induce flowering.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept
Photoperiodism is the response of plants to the relative lengths of day and night. The leaves perceive the photoperiod.

Step 2: Check the Assertion
Leaves are the organs that sense the photoperiod. They contain a light-absorbing protein, phytochrome, which starts the flowering response. So (A) is true.

Step 3: Check the Reason
Phytochrome exists as two interconvertible forms, P\(_r\) and P\(_{fr}\). Their balance tells the plant the length of the light and dark periods, so (R) is true.

Step 4: Link between them
The Reason names the protein and how it senses light and dark, which explains why leaves can induce flowering.

Final Answer:
Both statements are true and the Reason correctly explains the Assertion. \[ \boxed{\text{(A) }\text{Both (A) and (R) are true and (R) is the correct explanation of (A).}} \]