What type of development occurs immediately after fertilization and involves cell division?

Fetal development refers to the stage that begins after the embryonic phase, typically around the end of the eighth week of gestation when the basic structures of the organism have been formed. This process involves further growth and maturation of the fetus. However, immediately after fertilization, the critical process that occurs is actually a series of rapid cell divisions known as cleavage, which leads to the formation of a multicellular embryo.

This process is primarily classified as embryonic development, which occurs right after fertilization. During this stage, the zygote undergoes several rounds of division without increasing in overall size, eventually leading to the formation of a blastocyst that will implant into the uterine wall.

Implantation, which involves the embedding of the blastocyst into the uterine lining, occurs after the initial cell divisions are already underway. Conceptual development is a less commonly used term that does not specifically describe the biological processes occurring immediately post-fertilization. Thus, embryonic development is the correct context for the type of development that is characterized by immediate cell division following fertilization.