which is absent in arthropoda ?

Options

A. Compound eye
B. Chitinous exoskeleton
C. Closed blood vascular system
D. Malpighian tubules.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which feature is absent in arthropods. We need to analyze the given options: compound eye, cutaneous exoskeleton, closed blood vascular system, and Malpighian tubules.

2. **Analyzing the Options**:
- **Compound Eye**: Arthropods, such as insects and crustaceans, possess compound eyes, which are made up of multiple lenses and are well adapted for their environment.
- **Cutaneous Exoskeleton**: Arthropods have an exoskeleton made of chitin, which provides protection and support. This is a characteristic feature of arthropods.
- **Closed Blood Vascular System**: Arthropods do not have a closed circulatory system. Instead, they possess an open circulatory system where blood (hemolymph) is not contained within blood vessels but flows freely in the body cavity (hemocoel).
- **Malpighian Tubules**: These are excretory organs found in many arthropods, particularly insects, and are responsible for waste removal.

3. **Identifying the Absent Feature**: From the analysis, it is clear that the closed blood vascular system is not present in arthropods. They have an open circulatory system instead.

4. **Conclusion**: The correct answer to the question "which is absent in arthropoda?" is the **closed blood vascular system**.

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