What happens to a zygote after fertilization?

After fertilization, the zygote undergoes mitotic division, which is a critical process in the early stages of development. This division leads to cell multiplication without an increase in the overall size of the zygote. As the zygote divides, it transitions into a multicellular structure called a blastocyst, which is essential for implantation in the uterine lining and further development. This process is fundamental to embryogenesis, enabling the formation of various cell types that will later differentiate into all the tissues and organs of the body.

The other options do not accurately reflect what occurs post-fertilization, as muscle tissue and connective tissue development occurs later in the embryonic phase, and the zygote does not remain inactive. Its active division is a key characteristic of early embryonic development.