Correct Option
The correct option is (a).
Explanation
Epithelial tissue acts as the primary protective covering or lining for most organs and cavities within the animal body. Its structural organization is specialized to regulate the movement of materials and provide protection against mechanical injury, pathogens, and desiccation.
Statement-wise Analysis
- Statement 1 is Correct: Epithelial tissue forms a continuous sheet that covers the body surface and lines internal organs. This structure acts as a selective barrier, keeping different body systems separate and maintaining distinct internal environments for various organs.
- Statement 2 is Incorrect: Epithelial tissue is not directly connected to the underlying tissue. Instead, it rests on a thin, non-cellular, fibrous structure known as the basement membrane. This membrane separates the epithelium from the underlying connective tissue and provides structural support.
- Statement 3 is Incorrect: To function effectively as a barrier, epithelial cells are tightly packed with very little intercellular space and a minimal amount of cementing material between them. Large intercellular spaces would compromise the tissue's ability to act as a protective layer or a selective filter.
Key Takeaway: Epithelial tissue is characterized by tightly packed cells forming continuous sheets, the presence of a supporting basement membrane, and the absence of large intercellular spaces to ensure effective barrier function.