The kind of epithelium seen in respiratory tract is (a) Squamous epithelium (b) Ciliated epithelium (c) Glandular epithelium (d) Cuboidal epithelium

The respiratory tract is responsible for the exchange of gases, specifically the inhalation of oxygen and the exhalation of carbon dioxide. The epithelium lining the respiratory tract plays a vital role in this process, as well as in the protection of the tract against harmful substances and pathogens.

(a) Squamous Epithelium: These are flat, thin cells that form the lining of organs and structures where passive diffusion of gases, liquids, or ions occurs. Examples are found in the lining of blood vessels and air sacs of lungs (alveoli). (b) Ciliated Epithelium: This type of epithelium has hair-like structures (cilia) on the surface of the cells. The coordinated movement of the cilia helps to move substances like mucus, trapped dust, and pathogens along the surface of the tissue. Examples are found in the lining of the respiratory and reproductive tracts. (c) Glandular Epithelium: These cells are specialized to secrete substances like enzymes, hormones, and mucus. Examples of glandular epithelium can be found in salivary glands and endocrine glands. (d) Cuboidal Epithelium: These are cube-shaped cells that form the linings of organs where absorption, secretion, or excretion occurs. They can be found in renal tubules, glands, and parts of the respiratory tract like bronchioles.

Based on the characteristics of the respiratory tract and the four types of epithelial tissues, it can be determined that the respiratory tract has ciliated epithelium (option b). The presence of cilia is crucial in the respiratory tract, as they help move mucus and trapped particles, providing a protective function and ensuring proper breathing.

The correct answer is (b) Ciliated epithelium, as it is found in the respiratory tract and has the specific features that function in the airway's protection and function.