Biology · Kingdom Prokaryote

In prokaryotic cells, the flagella originate from the basal body, which is embedded in the cytoplasm and serves as the anchoring point for the flagellum. This structure is responsible for the rotation and movement of the flagella, aiding in cell motility. The basal body has a similar structural arrangement to centrioles, featuring microtubule triplets. The cell membrane, cell wall, and capsule, while important for cellular integrity and protection, do not serve as the origin of the flagella.

Option A is correct. In prokaryotic cells, the flagella originate from the basal body, which is an organelle that acts as the foundation for the flagellum, providing the necessary support and rotational motion. It is structurally similar to centrioles with a circular arrangement of microtubule triplets.

Option B is incorrect. The cell membrane is not the origin of the flagella; instead, it is the structure through which the basal body is embedded to secure the flagellum to the cell.

Option C is incorrect. Although the basal body passes through the cell wall, the cell wall itself is not the origin of the flagella. It provides structural support for the cell.

Option D is incorrect. The capsule is an outer covering that may surround the cell wall in some bacteria, but it does not serve as the origin of the flagella.