In Casuarina, modification occurs in

Options

A. Leaf
B. Stem
C. Floral bud
D. 1 & 2

Answer

**Step-by-Step Text Solution:**

1. **Identify the Organism**: The question is about Casuarina, a genus of trees commonly known as "shiok." It consists of around 17 species and is native to Australia and the Indian subcontinent.

2. **Understand the Modifications**: In Casuarina, modifications occur primarily in the leaves and the stem. The tree has slender, jointed, drooping twigs that resemble the structure of oysters.

3. **Describe Leaf Modifications**: The leaves of Casuarina are modified into tiny scale-like structures. This adaptation helps the tree to conserve water, which is essential for survival in its native habitats.

4. **Describe Stem Modifications**: The stem of Casuarina also plays a crucial role in photosynthesis due to the reduced leaf size. The green stems can carry out photosynthesis, compensating for the reduced leaf area.

5. **Evaluate the Options**: The question provides four options regarding where the modifications occur:
- Option 1: Leaf
- Option 2: Stem
- Option 3: Floral bud
- Option 4: One and two (leaf and stem)

6. **Select the Correct Answer**: Since modifications occur in both the leaves and the stem, the correct answer is option D: "One and two" (leaf and stem). The floral bud does not undergo significant modification in Casuarina.

**Final Answer**: The modification occurs in Casuarina in the leaf and stem (Option D: One and two).

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