Answer: transporting substances in a cell
Why: In eukaryotic cells, endomembrane system refers to the set of membranes present inside the cytoplasm which form single functional and developmental unit. The membranes are either connected directly or indirectly and exchange material with the help of vesicle transport. The main function of this system is to modify, pack and transport the proteins and lipids in and out of the cell. The main organelles which form the endomembrane system are- nuclear membrane, endoplasmic reticulum, Golgi apparatus, lysosomes, and vesicles.