For a critical study of secondary growth in plants, which one of the following pairs is suitable

Options

A. Deodar and ferm
B. Wheat and maiden hair fern
C. sugarcane and sunflower
D. teak and pine

Answer

To answer the question regarding a suitable pair for a critical study of secondary growth in plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Secondary Growth**: Secondary growth refers to the increase in girth or thickness of plants, primarily due to the activity of lateral meristems like the vascular cambium and cork cambium. This growth is typically seen in dicots.

2. **Identify Plant Types**: Recognize the difference between monocots and dicots:
- **Monocots** (e.g., grasses, sugarcane) generally do not exhibit secondary growth because they lack cambium.
- **Dicots** (e.g., sunflowers, teak) usually show secondary growth due to the presence of cambium.

3. **Analyze the Options**: Review the provided pairs to determine which includes one monocot and one dicot:
- **Option 1: Deodar and Fern** - Deodar is a dicot; fern is a pteridophyte. This pair does not include a monocot.
- **Option 2: Maidenhair and Weed** - Maidenhair is a pteridophyte; weed is a monocot. This pair does not include a dicot.
- **Option 3: Sugarcane and Sunflower** - Both are dicots. This pair does not provide a comparison between monocots and dicots.
- **Option 4: Teak and Pine** - Teak is a dicot (shows secondary growth), and pine is a monocot (does not show secondary growth). This pair is suitable for a comparative study.

4. **Conclusion**: The correct answer is **Option 4: Teak and Pine**, as it allows for a critical study of secondary growth in dicots versus the absence of it in monocots.