Palamnaeus (Scorpion) belongs to class arachnida because of

Options

A. 4 pairs of legs
B. Chelate legs
C. Sting
D. None.

Answer

To determine why Palamnaeus (Scorpion) belongs to the class Arachnida, we can analyze the characteristics that define this class. Here’s a step-by-step solution:

### Step 1: Understand the Classification
- **Class Arachnida** is a class within the phylum Arthropoda. It includes creatures such as spiders, scorpions, ticks, and mites.

### Step 2: Identify Key Characteristics of Arachnids
- The main characteristics that define members of the class Arachnida include:
1. **Body Structure**: The body is divided into two main parts: the cephalothorax (which is a fusion of the head and thorax) and the abdomen.
2. **Number of Appendages**: Arachnids have a total of eight appendages. This includes four pairs of legs and one pair of pedipalps.
3. **Absence of Antennae**: Unlike insects, arachnids do not have antennae.
4. **Respiration**: They breathe through a tracheal system or book lungs, which is adapted for terrestrial life.
5. **Excretion**: Excretion occurs through structures such as Malpighian tubules and Coxal glands.

### Step 3: Analyze the Options
- The options given in the question are:
1. Four pair of legs
2. Chelate legs
3. Stink
4. None

### Step 4: Select the Correct Answer
- Among the options, the most defining characteristic of Arachnida is the presence of **four pairs of legs**. This is a key feature that distinguishes arachnids from other classes within the phylum Arthropoda.

### Conclusion
- Therefore, Palamnaeus (Scorpion) belongs to the class Arachnida because of its **four pairs of legs**.

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