0.8 nm Amino Acid 2 nm Diameter of a DNA Alpha helix 4 nm Globular Protein 6 nm microfilaments 7 nm thickness cell membranes 20 nm Ribosome and its an awsome science 25 nm Microtubule 30 nm Small virus (Picornaviruses) 30 nm Rhinoviruses 50 nm Nuclear pore 100 nm HIV 120 nm Large virus (Orthomyxoviruses, includes influenza virus) 150-250 nm Very large virus (Rhabdoviruses, Paramyxoviruses) 150-250 nm small bacteria such as Mycoplasma 200 nm Centriole 200 nm (200 to 500 nm) Lysosomes 200 nm (200 to 500 nm) Peroxisomes 800 nm 1 µm (micrometer)giant virus Mimivirus (1 - 10 µm) the general sizes for Prokaryotes 1 µm Diameter of human nerve cell process 2 µm E.coli - a bacterium 3 µm Mitochondrion 5 µm length of chloroplast 6 µm (3 - 10 micrometers) the Nucleus 9-10 µm Human red blood cell (10 - 30 µm) Most Eukaryotic animal cells (10 - 100 µm) Most Eukaryotic plant cells 90 µm small Amoeba 120 µm Human Egg up to 160 µm Megakaryocyte up to 500 µm giant bacterium Thiomargarita up to 800 µm large Amoeba Or 1 mm (1 millimeter, 1/10th cm) 1 mm Diameter of the squid giant nerve cell up to 40mm Diameter of giant amoeba Gromia Sphaerica 120 mm Diameter of an ostrich egg (a dinosaur egg was much larger) 3 meters Length of a nerve cell of giraffe's neck