Both mitochondria and ribosome are so tiny structure, it can not be seen under light microscope. It needs more magnification to study the detail structure, hence electron microscope is best to use.
Ribosomes are small membrane less organelles and are the sites of protein synthesis.
It is present in are found in both eukaryotic and prokaryotic cells.
Ribosomes can either be present alone or in groups in cytoplasm while some ribosomes are attached to the endoplasmic reticulum called as rough endoplasmic reticulum.
These are composed of ribosomal protein and RNA, have two subunit larger and smaller subunit.
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