Epithelial Tissue in Frogs and Lizards

Introduction:
Epithelial tissue is one of the four primary types of animal tissue, along with connective, muscular, and nervous tissues. It covers the external and internal surfaces of the body and provides protection, absorption, secretion, and sensory functions. The skin is the largest organ of the body and is primarily composed of epithelial tissue.

Comparison of Frog and Lizard Skin:
- Frogs have smooth and moist skin, while lizards have dry and scaly skin.
- Despite these differences in appearance, both frog and lizard skin are made up of the same type of epithelial tissue.

Epithelial Tissue in Frog and Lizard Skin:
The correct answer is option D - Stratified squamous epithelium. This type of epithelium consists of multiple layers of flat, scale-like cells that are tightly packed together. It provides protection against mechanical abrasion, desiccation, and microbial invasion.

Explanation:
1. Stratified Squamous Epithelium:
- Stratified squamous epithelium is found in areas of the body that are subject to wear and tear, such as the skin.
- It consists of multiple layers of cells.
- The outermost layer of cells is flattened, while the deeper layers are cuboidal or columnar.
- This type of epithelium is well-suited to withstand physical stress and friction.

2. Skin of Frogs:
- Frogs have smooth and moist skin.
- The smoothness is due to the presence of a thin layer of mucus secreted by specialized glands in the skin.
- The moistness is maintained by the constant production of mucus and by the ability of the skin to absorb and retain water.

3. Skin of Lizards:
- Lizards have dry and scaly skin.
- The dryness is due to the absence of mucus glands and the presence of scales on the surface of the skin.
- The scales help to reduce water loss through evaporation.

4. Similarities in Epithelial Tissue:
- Despite the differences in appearance and texture, both frog and lizard skin are composed of stratified squamous epithelium.
- This type of epithelium provides protection against various external factors, including mechanical damage and microbial invasion.

Conclusion:
In conclusion, the skin of frogs and lizards may differ in terms of smoothness, moisture, and scaliness, but they are both composed of the same type of epithelial tissue: stratified squamous epithelium. This tissue provides protection against physical stress, desiccation, and microbial invasion.