What does the process of implantation refer to?

The process of implantation specifically refers to the embedding of the embryo in the endometrium, which is the lining of the uterus. After fertilization occurs in the fallopian tube, the fertilized egg, now called a zygote, undergoes several cell divisions as it travels toward the uterus. Once it reaches the uterus, this cluster of cells becomes a blastocyst and attempts to attach to the uterine lining, a critical step for establishing a pregnancy. Successful implantation allows for the exchange of nutrients and waste between the mother and the developing embryo, which is essential for growth and development.

The other processes mentioned in the choices involve different stages of reproduction and development. Fertilization refers to the union of sperm and egg, while the development of the fetus takes place after implantation when the embryo is fully established in the uterus. The release of the egg from the ovary, known as ovulation, occurs prior to fertilization and is a distinct phase in the menstrual cycle. Each of these processes plays a role in reproduction, but implantation specifically focuses on the embryo's integration into the uterine lining.