Which organelles are part of the membranous category?

The correct answer highlights the endoplasmic reticulum and golgi apparatus as part of the membranous category of organelles. These organelles have membranes that define their structure and function within the cell.

The endoplasmic reticulum (ER) is a network of membranes involved in protein and lipid synthesis. It exists in two forms: rough ER, which has ribosomes on its surface and is primarily responsible for protein synthesis and processing, and smooth ER, which is involved in lipid synthesis and detoxification processes.

The golgi apparatus is another membranous organelle that functions as a processing and packaging center for proteins and lipids produced in the ER. It modifies, sorts, and ships these molecules to their destinations—either within the cell or for export outside the cell.

In contrast, the other answer choices do not consist of membranous organelles. Ribosomes, while important for protein synthesis, are not membrane-bound. Centrioles and microvilli are structures involved in cellular cytoskeleton dynamics and surface area increase, respectively, and do not have membranes. Lastly, the cytoskeleton and cilia also lack membrane structures, as the cytoskeleton consists of protein filaments that provide support and shape to the cell, whereas