Cilia

Cilia are tiny bristle-like cytoplasmic projections on the free
cell surfaces. Their coordinated beating sets the cell itself or its environment in motion.

Cilia are found in many unicellular organisms, as well as in the cells of multicellular animals. They perform various functions - cell movement, food capture, excretion of waste products. The cilia are capable of vibrating in concert at a high frequency, causing the cell to move.

The structure of cilia includes an axoneme - a central fiber surrounded by cytoplasm. The axoneme provides rigidity to the cilium. The movement of cilia is controlled by a complex mechanism involving microtubules and dynein. Violation of eyelash function leads to serious diseases.

Thus, cilia are important organelles of the cell, allowing it to actively move and interact with the environment. Their structure and mechanism of action are not fully understood and remain the subject of active research.