Question

The amnion of mammalian embryo is derived from

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

Hint:

The amnion is a vital extraembryonic membrane that plays a crucial role in the development and protection of mammalian embryos.

Answer 1

The Correct Option is B

To answer the question of which tissue layers the amnion of a mammalian embryo is derived from, we need to understand the embryonic development process in mammals, particularly concerning the formation of extraembryonic membranes.

The amnion is one of the extraembryonic membranes that surround the embryo during development. It serves to enclose and protect the embryo by forming the amniotic cavity filled with amniotic fluid. This membrane arises from two germ layers:

1. Ectoderm: This is the outermost layer of cells or tissue of an embryo in early development, which gives rise to the epidermis and nervous tissue. In the context of the amnion, it forms the amniotic epithelium.
2. Mesoderm: This is the middle layer of an embryo that develops into muscles and the circulatory system, among other structures. For the amnion, it provides the connective tissue.

These two layers - ectoderm and mesoderm - together form the amnion, thus the derived correct answer is "ectoderm and mesoderm."

Let's analyze why the other options are incorrect:

• Ectoderm and endoderm: The endoderm does not contribute to the formation of the amnion; instead, it mainly gives rise to the linings of internal organs and some parts of the digestive and respiratory systems.
• Mesoderm and trophoblast: While the trophoblast contributes to the formation of the placenta, it is not involved in forming the amnion.
• Endoderm and mesoderm: As previously mentioned, endoderm is not involved in the formation of the amnion.

Therefore, the correct option that specifies the germ layers responsible for the formation of the amnion is ectoderm and mesoderm.