Final answer:
Small vesicles mediate communications between the interiors of the ER, Golgi apparatus, endosomes, and lysosomes.
Step-by-step explanation:
The communication between the interiors of the ER, Golgi apparatus, endosomes, and lysosomes is mediated by small vesicles.
The RER and Golgi apparatus are involved in sorting, tagging, packaging, and distributing lipids and proteins. Lysosomes are created by the budding of the membranes of the RER and Golgi, and they digest macromolecules and recycle organelles.
Small vesicles transport proteins and lipids between these organelles, facilitating communication and maintaining the flow of molecules within the endomembrane system.