Which part of the digestive system of human being hosts some symbiotic bacteria?

Options

A. Ileun
B. Duodenum
C. Pharynx
D. Caecum

Answer

To answer the question "Which part of the digestive system of human beings hosts some symbiotic bacteria?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Digestive System Structure**:
The human digestive system consists of various parts, including the mouth, pharynx, esophagus, stomach, small intestine (which includes the duodenum, jejunum, and ileum), and large intestine (which includes the cecum, colon, and rectum).

2. **Identify the Function of Each Part**:
- The mouth is responsible for the initial mechanical digestion of food.
- The pharynx serves as a passage for both food and air.
- The esophagus transports food to the stomach.
- The stomach further digests food chemically and mechanically.
- The small intestine is where most digestion and absorption of nutrients occur.
- The large intestine is primarily involved in water absorption and the formation of feces.

3. **Focus on the Large Intestine**:
The large intestine consists of three parts: the cecum, colon, and rectum.

4. **Identify the Cecum**:
The cecum is a small blind sac at the beginning of the large intestine. It is known to host a variety of symbiotic bacteria that aid in the fermentation of undigested materials.

5. **Conclusion**:
Based on the information gathered, the part of the digestive system that hosts symbiotic bacteria is the cecum.

### Final Answer:
The correct answer is **D. Cecum**.

---