Malpighian tubules of cockroach and septal nephridia of earthworm share one common character

Options

A. Both are segmented
B. Both have ciliated
C. Both discharge excretory matter into digestive tract
D. Both release excretory matter only outside.

Answer

### Step-by-Step Solution:

1. **Identify the Excretory Structures**: The question asks about the common character shared by the Malpighian tubules of cockroaches and the septal nephridia of earthworms. First, we need to understand what these structures are and their functions.

2. **Location of Malpighian Tubules**: Malpighian tubules are excretory organs found in cockroaches. They are located in the abdominal body cavity and empty their contents into the junction between the midgut and hindgut.

3. **Location of Septal Nephridia**: Septal nephridia are the excretory structures in earthworms. They are situated on the intersegmental septum, specifically between the 15th and 16th segments, and also empty into the digestive tract.

4. **Common Character Analysis**: Both the Malpighian tubules and septal nephridia are involved in excretion and both discharge their excretory products into the digestive tract. This is a significant common character as they both utilize the digestive system for excretion.

5. **Reviewing the Options**:
- **Option A**: Both are segmented - This is incorrect as Malpighian tubules are not segmented.
- **Option B**: Both have ciliated structures - This is incorrect as cilia are not a feature of Malpighian tubules.
- **Option C**: Both discharge excretory matter into the digestive tract - This is correct as both structures empty their excretory products into the digestive system.
- **Option D**: Both release excretory matter only outside - This is incorrect since septal nephridia release their excretory matter into the digestive tract.

6. **Conclusion**: The correct answer is that both the Malpighian tubules of cockroaches and the septal nephridia of earthworms discharge their excretory matter into the digestive tract.