5. mitochondria
Muscle cells have numerous mitochondria, more than other types of cells, so that they can quickly and forcefully respond to the body’s constant need for various types of movement.
8. ribosomes
Ribosomes are small organelles and are the sites of protein synthesis (or assembly). They are made of ribosomal protein and ribosomal RNA, and are found in both eukaryotic and prokaryotic cells. Unlike other organelles, ribosomes are not surrounded by a membrane.