Question

The amnion of mammalian embryo is derived from

• A. ectoderm and mesoderm
• B. mesoderm and trophoblast
• C. endoderm and mesoderm
• D. ectoderm and endoderm

Answer 1

The Correct Option is A

The question asks about the developmental origin of the amnion in a mammalian embryo. Let's explore the options and find the correct answer.

The amnion is a membranous sac that surrounds and protects the embryo in its early stages of development. It's filled with amniotic fluid, which acts as a cushion for the developing embryo.

To understand the origins of the amnion, we need to consider the layers of cells from which it develops:

1. Ectoderm: This is the outermost layer of the embryo, primarily responsible for forming the skin and nervous system.
2. Mesoderm: This is the middle layer that contributes to developing muscles, bones, and the circulatory system.
3. Endoderm: This innermost layer forms the lining of the digestive tract and other internal organs.

In mammals, the amnion is derived from a combination of ectoderm and mesoderm, also known as somatopleure. Let's consider the options:

• Ectoderm and mesoderm: Correct. The amnion forms from these layers through their contribution to somatopleure.
• Mesoderm and trophoblast: Incorrect. The trophoblast is involved in forming the placenta, not the amnion.
• Endoderm and mesoderm: Incorrect. The endoderm does not contribute to the formation of the amnion.
• Ectoderm and endoderm: Incorrect. The endoderm is not involved in the formation of the amnion.

Thus, the correct answer is that the amnion of a mammalian embryo is derived from ectoderm and mesoderm. This understanding is crucial in embryology and helps us comprehend the complex process of mammalian development.