What term describes the event when an egg is fertilized by the sperm?

The term that describes the event when an egg is fertilized by sperm is conception. During conception, the sperm successfully penetrates the egg, leading to the formation of a zygote. This process is the initial step in creating a pregnancy, as it marks the moment when genetic material from both parents combines to form a new life.

Implantation refers to the stage that occurs after conception, where the fertilized egg, now a blastocyst, attaches itself to the lining of the uterus. Ovulation is the process whereby an egg is released from the ovary, making it available for fertilization, but it does not encompass the act of fertilization itself. Menstruation is the shedding of the uterine lining when pregnancy does not occur, which is unrelated to the fertilization event. Therefore, conception is the precise term that captures the moment of fertilization.