Arthropods are the first to have

Options

A. cephalisation
B. blood vascular system
C. true muscles
D. striated muscles

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:** The question asks what characteristics arthropods are the first to have among the given options.

2. **Analyzing the Options:**
- **Option 1: Cephalization** - This refers to the concentration of sensory organs and nervous tissue at the anterior end of the organism. Cephalization is first seen in flatworms (Platyhelminthes), not arthropods.
- **Option 2: Blood Vascular System** - A blood vascular system is a characteristic of vertebrates. Arthropods do not possess a true blood vascular system; they have an open circulatory system.
- **Option 3: True Muscles** - True muscles are generally associated with vertebrates and are not a distinguishing feature of arthropods.
- **Option 4: Striated Muscles** - Striated muscles are voluntary muscles that are first observed in arthropods. These muscles allow for more complex movements and are a significant advancement in the evolution of muscle tissue.

3. **Conclusion:** After analyzing all the options, the only correct answer is that arthropods are the first to have **striated muscles**.

**Final Answer:** Arthropods are the first to have striated muscles.

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