Organogenesis in the fetus takes place during which period?

• A. 6 weeks - birth
• B. 0 - 10 days after conception
• C. 10 days - 6 weeks after conception
• D. 6 - 10 days after conception

Answer: (C)

The key idea is that organ formation happens during the embryonic period, when the major organ systems arise from the germ layers formed after fertilization. This developmental window starts a bit after conception—around day 10 when the germ layers begin organizing—and continues through roughly the end of the sixth week after conception. That timing fits the period when organs are taking shape, distinguishing it from the earlier pre-embryonic stages (0–10 days and around day 10) and from the later fetal period (after about the sixth week), when growth and maturation dominate rather than new organ formation. Among the given options, the span from about day 10 after conception to six weeks post-conception best captures the period of organogenesis.