Extra embryonic membrane amnion is not found in amphibians because

Options

A. They lay eggs in water
B. Egg hatches in tadpole
C. Amphibious habit
D. They have smooth skin

Explanation

**Step-by-Step Solution:**

1. **Understanding Extra Embryonic Membranes**: Extra embryonic membranes are structures that provide protection and support to the developing embryo. The amnion is one such membrane that surrounds the embryo in a fluid-filled sac, providing a stable environment.

2. **Identifying the Habitat of Amphibians**: Amphibians, such as frogs and salamanders, typically lay their eggs in aquatic environments (water). This is crucial for their reproductive strategy.

3. **Egg Development in Water**: The eggs of amphibians are usually surrounded by a jelly-like substance, which provides some protection and keeps them moist. When the eggs hatch, they develop into aquatic larvae (tadpoles), which also live in water.

4. **Comparison with Other Vertebrates**: Unlike amphibians, reptiles, birds, and mammals lay their eggs on land or have adaptations that allow their embryos to develop in a terrestrial environment. These groups have evolved the amnion to protect their eggs from desiccation (drying out) and to provide a stable environment.

5. **Conclusion**: Since amphibians lay their eggs in water, they do not require the amnion for protection against desiccation. The aquatic environment provides the necessary conditions for the development of their embryos, making the amnion unnecessary.

**Final Answer**: The extra embryonic membrane amnion is not found in amphibians because they lay eggs in water.

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