How many parent cells do duck billed platypus have?

The duck-billed platypus, a monotreme, has a unique reproductive system that involves laying eggs rather than giving live birth. Female platypuses lay one to three eggs at a time, which they incubate by curling around them. After hatching, the young are fed with milk produced by the mother. Therefore, in terms of parent cells, each egg originates from one female parent cell (the ovum) and is fertilized by a male sperm cell.