1. If a cell uses a different genetic code (and remember that a few funky protists do), then it must have different tRNA molecules.
2. A single mRNA molecule can only be translated once.
3.In eukaryotic cells, the mature mRNA molecule starts with an AUG to allow the ribosome to begin protein synthesis with a methionine.
4.All ribosomes are associated with the rough endoplasmic reticulum; in fact it gets its name (“rough”) from how ribosomes look in the electron microscope lining its surface.