Golgi Apparatus

The Golgi apparatus consists of flattened, stacked sacs called cisternae that show a distinct structural and functional polarity, a feature highlighted in NCERT Class 11, Chapter 8 (Cell: The Unit of Life). Its convex cis or forming face lies close to the endoplasmic reticulum and the nucleus and receives transport vesicles carrying newly synthesised material from the ER. After modification, products move toward the concave trans or maturing face, from which packaged vesicles are dispatched. The option naming the trans face is therefore wrong for the receiving role, because that face is the site of exit, not entry. The statement that both faces are identical contradicts the well-documented cis-to-trans polarity that allows sequential processing of glycoproteins and glycolipids. Mentioning the lysosomal lumen is irrelevant, since the lysosome is a separate organelle formed from Golgi-derived vesicles rather than a Golgi face. As material passes from the cis to the trans cisternae, enzymes progressively add and trim sugar residues, so the Golgi behaves like an assembly line in which the order of the cisternae matches the order of the chemical modifications. This is why the organelle must possess two functionally distinct ends rather than a uniform structure. A directional sanity check confirms the answer: material must enter at the face nearest its ER source, so the cis face is the correct receiving end of the organelle.