Final answer:
Tubules or follicles in simple epithelia are formed by specialized epithelial cells suited for functions such as absorption and secretion. Cuboidal epithelia line kidney tubules and gland ducts, while columnar epithelia line parts of the digestive system and female reproductive tract. Ciliated columnar epithelia help in the removal of particles with their cilia.
Step-by-step explanation:
Tubules or follicles are formed in simple epithelia through the specialization of epithelial cells to adapt to their function in absorption, secretion, and filtration. In simple cuboidal epithelium, the cells are cube-shaped with centrally located nuclei. These epithelia line the kidney tubules and the ducts of glands. Their structure is vital for their role in secretion and absorption of molecules. Similarly, in simple columnar epithelium, which is made up of tall, column-like cells, the nucleus is elongated and located at the basal end.
These cells not only absorb and secrete molecules but in the case of ciliated columnar epithelium, they have cilia on their apical surfaces which are involved in moving particulate matter out of the fallopian tubes or the respiratory system. The structures of these epithelial cells, including the presence of microvilli or cilia, are crucial for the enhanced surface area and function of the tubules or follicles they form.