Question

The extra embryonic membranes of mammalian embryo are derived from

• A. inner cell mass
• B. formative cells
• C. trophoblast
• D. follicle cells

Answer 1

The Correct Option is C

The question is about the origin of extra-embryonic membranes in a mammalian embryo. Here's a step-by-step explanation to understand the correct answer:

1. Understanding Extra-embryonic Membranes:

   Extra-embryonic membranes are structures that support the embryo, providing protection and facilitating nutrient and waste exchange. They include the amnion, chorion, yolk sac, and allantois.

2. The Role of Trophoblast:

   The trophoblast is the outer layer of cells in the early embryo that contributes significantly to the formation of the placenta and the extra-embryonic membranes. It plays a crucial role in nutrient exchange between the mother and the developing fetus.

3. Eliminating Incorrect Options:
   • Inner Cell Mass: This part of the embryo develops into the fetus itself, not the extra-embryonic structures.
   • Formative Cells: This is not a specific term used in embryology that directly relates to the formation of these membranes.
   • Follicle Cells: These are part of the ovary and are involved in the maturation of the egg, not the embryo or its membranes.
4. Conclusion:

   Therefore, the extra-embryonic membranes of the mammalian embryo are derived from the trophoblast.