Arthropoda is differentiated from annelids by

Options

A. Segmented body
B. Absence of nephridia
C. Eyes
D. None of the above.

Answer

To differentiate Arthropoda from Annelida, we need to analyze the characteristics of both phyla. Here’s a step-by-step solution to the question:

### Step 1: Understand the Basic Characteristics
Both Arthropoda and Annelida are segmented animals. They share the characteristic of having a segmented body, which means that this feature does not differentiate them.

**Hint:** Look for characteristics that are unique to one phylum and not present in the other.

### Step 2: Examine the Excretory Structures
Annelids possess nephridia as their excretory structures, which help in the elimination of waste. In contrast, Arthropoda have different excretory structures, such as Malpighian tubules and green glands, which serve the same purpose.

**Hint:** Consider the excretory systems of both phyla to find a distinguishing feature.

### Step 3: Analyze the Eyes
Both Arthropoda and Annelida have eyes, but the types of eyes can vary. Arthropods may have compound eyes, while annelids typically have simple eyes. However, this feature is not exclusive enough to differentiate the two phyla.

**Hint:** Think about whether the presence or type of eyes is a significant differentiating factor.

### Step 4: Evaluate the Options
1. **Segmented Body**: Present in both phyla, so it cannot be the answer.
2. **Absence of Nephridia**: This is true for Arthropoda, as they do not have nephridia but have Malpighian tubules instead.
3. **Eyes**: Both have eyes, so this option is not a differentiating factor.
4. **None of the Above**: This option is incorrect since we have identified a valid differentiating feature.

### Conclusion
The correct answer is that Arthropoda is differentiated from Annelida by the **absence of nephridia**.

**Final Answer:** Absence of nephridia.