Following are the differences between monocot and dicot stem . Which ones are correct ?
`{:(,"Phylloclade","Phyllode","Cladode"),((i),"Opuntia","Asparagus","Acacia"),((ii),"Xylem","Exarch","Endarch"),((iii),"Pith","Absent","Present"),((iv),"Bundle sheath","Sclerenchymatous","Parenchymatous"):}`

Options

A. i and ii
B. iii and iv
C. i and iii
D. ii and iv

Answer

To solve the question regarding the differences between monocot and dicot stems, we will analyze each of the provided options step by step.

### Step 1: Analyze the first option regarding Phylloclade, Phyllode, and Cladode
- **Phylloclade**: A flattened stem that performs photosynthesis. Example: Opuntia (Cactus).
- **Phyllode**: A modified stem that resembles a leaf and is capable of photosynthesis. Example: Asparagus.
- **Cladode**: Similar to phylloclade, a flattened stem that also performs photosynthesis. Example: Acacia.

**Conclusion**: The first option is correct as all three terms are associated with the examples given.

### Step 2: Analyze the second option regarding Xylem structure
- **Exarch**: In this arrangement, the protoxylem is located towards the outside, and metaxylem is towards the center. This is typical in dicots.
- **Endarch**: In this arrangement, the protoxylem is located towards the center, and metaxylem is towards the outside. This is typical in monocots.

**Conclusion**: The second option is incorrect because it misrepresents the xylem structure in monocots and dicots.

### Step 3: Analyze the third option regarding Pith presence
- In monocots, the pith is typically absent.
- In dicots, the pith is present.

**Conclusion**: The third option is correct as it accurately describes the presence of pith in dicots and its absence in monocots.

### Step 4: Analyze the fourth option regarding Bundle Sheath
- **Sclerenchymatous**: This type of bundle sheath is typically found in dicots.
- **Parenchymatous**: This type of bundle sheath is typically found in monocots.

**Conclusion**: The fourth option is incorrect as it misrepresents the type of bundle sheath associated with monocots and dicots.

### Final Conclusion
The correct options are:
- **1 (Phylloclade, Phyllode, Cladode)**
- **3 (Pith presence)**