No, the endomembrane system lies between the nuclear envelope and the cell membrane; dis-including both.

The Endoplasmic reticulum and the Golgi apparatus are two members of the endomembrane system. Google endomembrane system to get the complete picture.

In your cell, this is where the endomembrane system comes in a cell image because one is studded with small ribosomes and one is not.

In your cell, this is where the endomembrane system comes in a cell image because one is studded with small ribosomes and one is not.

In your cell, this is where the endomembrane system comes in a cell image because one is studded with small ribosomes and one is not.

No. The endomembrane system consists of the endoplasmic reticulum and the Golgi apparatus - i.e things that are formed within the cell. The mitochondria was originally formed from a captured bacterial cell - as it has it's own DNA and its own ribosomes (as well as very bacterial like proteins). It is a separate organelle on its own, although it will have connections with the endomembrane system it is not considered part of it.