Assertion: Photoperiodism of flowering is phytochrome-regulated process.
Reason: Active form of phytochrome (Pfr) directly induces floral induction in shoot buds.

Options

A. If both assertion and reason are true and reason is the correct explaination of assertion
B. If both assertion and reason are true but reason is not correct explaination of assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false.

Explanation

To solve the assertion-reason question, let's break it down step by step:

### Step 1: Understand the Assertion
The assertion states that "Photoperiodism of flowering is a phytochrome-regulated process."
- Photoperiodism refers to how plants respond to the length of day and night, which influences their flowering.
- Phytochrome is a pigment in plants that plays a crucial role in this process. It exists in two forms: Pr (inactive) and Pfr (active).

**Hint:** Consider how light affects plant behavior and the role of phytochrome in this process.

### Step 2: Analyze the Reason
The reason states that "Active form of phytochrome (Pfr) directly induces floral induction in shoot buds."
- The active form of phytochrome, Pfr, is indeed responsible for triggering flowering in response to light conditions.
- When plants are exposed to light, Pfr accumulates, and this accumulation is what leads to the induction of flowering.

**Hint:** Think about the relationship between light exposure and the biochemical processes in plants that lead to flowering.

### Step 3: Evaluate the Truth of Both Statements
- Both the assertion and the reason are true. The assertion correctly identifies that photoperiodism is regulated by phytochrome, and the reason accurately describes the role of Pfr in floral induction.
- Furthermore, the reason provides a correct explanation for the assertion, as it details how Pfr is involved in the flowering process.

**Hint:** Reflect on how both statements relate to each other and confirm their validity.

### Step 4: Conclusion
Since both the assertion and reason are true, and the reason correctly explains the assertion, we can conclude that the correct answer is that both statements are true and the reason is the correct explanation of the assertion.

**Final Answer:** Both assertion and reason are true, and the reason is the correct explanation of the assertion.