Final answer:
Mitochondrial and chloroplast proteins are primarily made in the cytosol of eukaryotic cells. The electron transport systems in prokaryotes are found in the cytoplasmic membrane.
Step-by-step explanation:
Most mitochondrial and chloroplast proteins are synthesized in the cytosol of the cell before they are transported to their respective organelles. These proteins are encoded by nuclear DNA, translated in the cytosol, and then imported into the mitochondria or chloroplasts where they carry out various functions. Both mitochondria and chloroplasts also have their own small set of DNA and can synthesize some of their own proteins. However, the majority of proteins necessary for their function are imported from the cytosol. This relationship is due to the endosymbiotic theory, which suggests that these organelles originated as separate prokaryotic organisms that were integrated into the cell.
Concerning the location of electron transport systems in prokaryotes, the correct option is D. the cytoplasmic membrane. Unlike eukaryotic cells, where the electron transport chain is located in the inner mitochondrial membrane, in prokaryotic cells, it is embedded in the cytoplasmic membrane because they lack mitochondria.