Question

the ______ is an organelle of the endomembrane system that serves as a sort of \post office,\ where some proteins are processed and sent to their destinations. lysosome ribosome nucleus endoplasmic reticulum golgi apparatus

Explanation:

The Golgi Apparatus is part of the endomembrane system. It modifies, sorts, and packages proteins and lipids, acting like a cellular "post office" to send them to their correct destinations. Lysosomes digest waste, ribosomes make proteins, the nucleus holds genetic material, and the endoplasmic reticulum synthesizes and transports molecules, none of which match the "post office" function described.

Answer:

Golgi Apparatus