The surface area of intestine in earthwrom is greatly increased by the presence of

Options

A. Gizzard
B. Typhlosole
C. Buccal cavity
D. Calciferous glands

Explanation

**Step-by-Step Solution:**

1. **Understanding the Structure of the Earthworm's Alimentary Canal:**
- The alimentary canal of the earthworm consists of several parts: mouth, buccal cavity, pharynx, esophagus, gizzard, stomach, and intestine. Each part serves a specific function in digestion.

2. **Identifying the Key Features of the Intestine:**
- The intestine of the earthworm is located from the 15th segment to the last segment of the body. It plays a crucial role in the absorption of nutrients.

3. **Recognizing the Special Structures in the Intestine:**
- Within the intestine, there are structures called intestinal saccae that project from the intestine. However, the most significant feature that increases the surface area for absorption is the presence of the typhlosol.

4. **Defining the Typhlosol:**
- The typhlosol is a median fold of the dorsal wall of the intestine that extends inward. This folding increases the effective surface area of the intestine, enhancing the absorption of digested nutrients.

5. **Evaluating the Options Given:**
- **Gizzard:** Does not have internal folds; it is primarily for grinding food.
- **Typhlosol:** Correct answer; it is the internal fold that increases surface area.
- **Buccal Cavity:** No internal folding; it is involved in the initial stages of digestion.
- **Calciferous Gland:** Releases alkali to neutralize acids but does not increase surface area.

6. **Conclusion:**
- The presence of the typhlosol in the intestine of the earthworm greatly increases the surface area, facilitating better absorption of nutrients.

**Final Answer:**
The surface area of the intestine in the earthworm is greatly increased by the presence of **typhlosol**.

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