The entire eukaryotic flagellum or cilia is intracellular. What is the validity of this statement?

The statement that the entire eukaryotic flagellum or cilia is intracellular is true because these structures, while they extend from the surface of the cell, are fundamentally composed of cytoplasmic components. In eukaryotic cells, flagella and cilia arise from the basal body, which is an organelle located within the cell. These structures are made of microtubules arranged in a characteristic "9+2" configuration and are surrounded by the plasma membrane of the cell.

The flagellum or cilia function as extensions of the cytoskeleton, which is a network within the cell that helps maintain its shape, enables cell movement, and facilitates intracellular transport. Although they protrude beyond the cell membrane, their origin is firmly rooted within the intracellular environment. This connects their structure and function with the internal cell processes, reinforcing the idea that they are, in essence, an extension of the cell rather than an entirely separate or external entity.