After fertilization the zygote increases in size and travels down the fallopian tube to become embedded in the walls of the womb. This process is called:

Explanation

After fertilization, the zygote undergoes a series of cell divisions, forming a structure known as a blastocyst. The blastocyst then travels down the fallopian tube and eventually reaches the uterus. The process by which the blastocyst becomes embedded in the walls of the uterus is called implantation. Implantation generally occurs around 6-10 days after fertilization. The embryo, at this stage, is a multicellular structure, and the process of implantation marks the beginning of the embryonic stage of development. Once implanted, the cells of the blastocyst continue to differentiate, and the early structures of the developing fetus begin to form.