if there is a source of water and single celled organisms, life will be possible on that planet. The planet will need a atmosphere so 1. it will have its own gravity 2. and so that gas molecules ( including oxygen) will not be able to escape into space. the world population will be roughly 10.7 billion people so the planet will need to be spacious. A planet as described would be perfect if you take the right measures. if it has single celled organisms than its proven that it can and will sustain life. So, the planet has a water source, contains living organisms, is spacious, and has a atmosphere.
The endoplasmic reticulum can either be smooth or rough, and in general its function is to produce proteins for the rest of the cell to function. The rough endoplasmic reticulum has on it ribosomes, which are small, round organelles whose function it is to make those proteins.
Maybe this helps ? Please look at the picture
