Each cell has an average of 300-400 mitochondria. Advanced plant cells contain 100-3000 mitochondria. Liver and kidney cells contain 1000 or more mitochondria. Human sperm has 20 mitochondria. A sea urchin egg has 140,000 mitochondria, an amphibian egg has 300,000, and an Amoeba has 500,000. Mammalian red blood cells do not contain mitochondria.