Most cells are microscopic and 20-30 micrometers. A typical body cell is about 10 µm in size and weighs 1 ng. The smallest cell is Mycoplasma (Mycoplasma gallisepticum, PPLO-Pleuro Pneumonia Like Organism) with a diameter of 0.1 micrometer. The largest cell is the ostrich egg (17×12.5 cm). The smallest cell in the human body is the sperm and the largest cell is the egg (diameter 0.1 mm). The diameter of red blood cells is 7-8 micrometers. A human pea neuron cell is 1.37 meters long (from the base of the spinal cord to the big toe). Acetabularia algae are the largest cells in the plant kingdom. Its length is 5-10 cm. The longest cell is the bark fiber of Bochmeria nivea plant. Its length is 55 meters. The cells of plant fibers such as cotton, jute, palm etc. are quite long.