All of the above points are valid for fossils' contributions in understanding the process of evolution. They allow us to study the ancestry, we can see the homologous organs or structures, if fossils are well-preserved; different fossils can lead us to follow the cycles of the changes that occurred during macroevolutions, and fossils can be used to study different populations which had different body structures for surviving in different environmental conditions.
There are four main organelles:
Nucleus
Ribosome
Rough Endoplasmic Reticulum
Golgi Apparatus
However, the ribosome is the most responsible for making protein, even though the other 3 are also important. It isn't a cell organelle but a cell structure that produces proteins.
That process is called homeostasis
