Following fertilization, a zygote divides and soon becomes a multicelled embryo with many different cell types. Which statement best explains this development?
1) The zygote undergoes mitosis to produce more cells.
2) The zygote differentiates into various cell types.
3) The zygote forms a blastocyst before developing into an embryo.
4) The zygote undergoes meiosis to produce haploid cells.