frog is amphibian because

Options

A. Aldosterone
B. thyroxine
C. pituitary hormone
D. oxytocin

Answer

**Step-by-Step Solution:**

1. **Understanding the Term "Amphibian":** The term "amphibian" comes from the Greek word "amphibios," which means "living a double life." This indicates that amphibians can live both in water and on land.

2. **Life Cycle of Frogs:** Frogs begin their life cycle in water as eggs, which hatch into tadpoles. Tadpoles are aquatic and breathe through gills. As they grow, they undergo metamorphosis, transforming into adult frogs that can live on land.

3. **Role of Hormones:** The metamorphosis from tadpole to adult frog is regulated by hormones. One key hormone involved in this process is thyroxine, which is secreted by the thyroid gland. Thyroxine plays a crucial role in the development and transformation of the frog.

4. **Adaptations for Dual Life:** Adult frogs have adaptations that allow them to thrive in both environments. They have lungs for breathing air on land, and their skin can absorb water and oxygen, which is essential for their survival in both habitats.

5. **Conclusion:** Frogs are classified as amphibians because they have a life cycle that includes both aquatic and terrestrial stages, and they possess the physiological adaptations necessary to survive in both environments.