By the end of month 2, the organism is described as which stage?

• A. It is still an embryo
• B. It is a fetus
• C. It is a zygote
• D. It is a morula

Answer: (B)

The main idea is the sequence of prenatal development stages: zygote, morula, blastocyst, embryo, then fetus. By the end of month two, about eight weeks after conception, many introductory lessons shift the label to fetus because the growth focus has moved from early formation to ongoing development and refinement of body structures. The other stages occur earlier: a zygote is the initial fertilized cell, a morula is the early solid ball of cells, and the embryo covers the period of organ formation up to roughly the end of the eighth week. In this context, labeling the developing organism as a fetus at the end of month two reflects that transition in many teaching resources.