What is the Largest Cell?

The female ovum (egg cell) is the largest cell in the human body.

• Diameter: approximately 0.1 mm (100 micrometres)
• It is the only human cell visible to the naked eye (just barely)
• It is produced in the ovaries during the process of oogenesis
• The ovum contains the genetic material from the mother (23 chromosomes) and provides the cytoplasm and nutrients for the developing embryo

Smallest human cell: The male sperm cell (specifically its head) is considered the smallest human cell.

The Ostrich egg is the largest single cell in the world.

• An ostrich egg can measure about 15 cm long and 13 cm wide, weighing up to 1.5 kg
• The entire egg (the yolk specifically) is a single cell — the largest known cell in the biological world
• For comparison, a hen's egg yolk is also a single cell

Longest cell in the human body: While the ovum is the largest by volume/diameter, the neurons (nerve cells) can be the longest cells. Motor neurons that run from the spinal cord to the toes can be over 1 metre long.