The shape of a cell is maintained by which of the following?

The maintenance of cell shape is primarily due to the cytoskeleton, which consists of three main components: microfilaments, intermediate filaments, and microtubules. Microtubules play a crucial role in providing structural support to cells, enabling them to maintain their shape, resist deformation, and facilitate movement within the cell.

Microtubules are dynamic structures made of tubulin proteins that can rapidly grow and shrink, allowing cells to adjust their shape as needed. They form a network throughout the cytoplasm, anchoring organelles and providing tracks along which vesicles and other cargo can be transported.

While spindle fibers, which are specialized microtubules, are essential for chromosome separation during cell division, they do not generally contribute to the overall shape of non-dividing cells. Ribosomes are primarily involved in protein synthesis and do not have a role in maintaining cell shape. Similarly, centrioles are associated with organizing microtubules during cell division and do not directly influence the cell's structural integrity.

Thus, microtubules are the primary structural components that ensure a cell maintains its shape under various conditions.