Choose incorrect option w.r.t shoot apex

Options

A. terminal position
B. produces nodes and internodes
C. primary meristem
D. differentiated into four histogens

Answer

To solve the question "Choose incorrect option w.r.t shoot apex," we need to analyze the statements related to the shoot apex and identify which one is incorrect. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Shoot Apex
The shoot apex, also known as the shoot apical meristem, is the growing tip of a plant shoot. It is responsible for the vertical growth of the plant and is derived from the meristematic tissue in the plumule of the embryo.

**Hint:** Remember that the shoot apex is crucial for the growth and development of the plant.

### Step 2: Identify the Structure of the Shoot Apex
The shoot apex is typically conical or dome-shaped and is located at the tip of the stem. It is protected by young leaves that are formed by it.

**Hint:** Visualize the shoot apex as the top part of a plant, where new growth occurs.

### Step 3: Differentiate Between Bud Types
The shoot apex can form two types of buds:
- **Terminal Buds:** Located at the tip of the stem.
- **Lateral (Axillary) Buds:** Located in the axils of leaves and are usually in an inactive state.

**Hint:** Terminal buds promote vertical growth, while lateral buds can lead to branching.

### Step 4: Understand the Meristematic Activity
The shoot apex is a primary meristem, meaning it contributes to the elongation of the plant. It is not a secondary meristem, which is involved in increasing the girth of the plant later in its life.

**Hint:** Primary meristems are involved in lengthening, while secondary meristems are involved in thickening.

### Step 5: Analyze the Histogen Theory
According to the histogen theory proposed by scientist Henston in 1870, the shoot apical meristem is differentiated into three histogens:
1. **Dermatogen:** Forms the epidermis (outer layer).
2. **Periblem:** Forms the cortex and endodermis.
3. **Pleurome:** Forms the vascular tissues (pericycle, vascular bundles, medullary rays, and pith).

**Hint:** Remember that the histogen theory states there are three, not four, histogens.

### Step 6: Identify the Incorrect Statement
Based on the information provided, the incorrect statement regarding the shoot apex is that it is differentiated into four histogens. In reality, it is differentiated into three histogens.

**Hint:** Look for statements that contradict established theories or facts about plant anatomy.

### Conclusion
The incorrect option with respect to the shoot apex is the one that states it is differentiated into four histogens.

### Final Answer
The answer to the question is the statement claiming that the shoot apex is differentiated into four histogens, which is incorrect.

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