Question

The formation of every major organ of the body takes place during

• A. Prenatal period
• B. Germinal period
• C. Embryonic period
• D. Foetal period

Hint:

Organogenesis (organ formation) occurs during the Embryonic period (weeks 3 to 8), making this the most critical stage for congenital birth defects.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Prenatal development is the process of growth from fertilization to birth.
This development is divided into three successive periods: the germinal period, the embryonic period, and the fetal period.

Step 2: Detailed Explanation:
Let us analyze each of these prenatal stages:
Germinal Period (fertilization to 2 weeks): This stage begins with the formation of the zygote, followed by cell division and implantation into the uterine wall. No organ development occurs during this phase.
Embryonic Period (weeks 3 to 8 of gestation): This is the stage of rapid development where the blastocyst differentiates into three germ layers: the ectoderm, mesoderm, and endoderm.
This period is characterized by organogenesis—the process of organ formation.
By the end of the eighth week, all major organs and systems of the body (including the heart, brain, limbs, and digestive tract) have begun to form.
Because of this rapid development, the embryo is highly vulnerable to environmental teratogens (such as drugs or infections) during this stage.
Fetal Period (week 9 to birth): This long stage focuses on the growth, maturation, and refinement of the organs established during the embryonic period.
While the prenatal period includes all three stages, organogenesis specifically occurs during the embryonic period.

Step 3: Final Answer:
The formation of major organs takes place during the Embryonic period.