Question

Select the correct pair of endodermal derivatives
a. The adrenal medulla, the dermis of the skin
b. Lungs, thyroid gland
c. The lymphatic vessel, vagina
d. Retina, tonsil

Answer 1

Hint: The human body is made up of three germ layers that are described during the installation phase. These germ layers are ectoderm, endoderm, and mesoderm. The ectoderm gives rise to the central nervous system (the brain and spinal cord); the peripheral nervous system; the sensory cell etc. It is the innermost layer present inside our body.

Complete answer:
There are three primary firm layers in the very early embryo. The other two layers are the mesoderm which is the middle layer. The other layer is the endoderm (most proximal layer), with the ectoderm as the most exterior (or distal) layer. Generally speaking, the ectoderm differentiates to form the nervous system (spine, peripheral nerves, and brain), tooth enamel, and the epidermis. It also forms the lining of the mouth, anus, nostrils, sweat glands vertebrates this.

Invertebrates the ectoderm has endodermis: external endoderm (also known as a surface accident. So option B is correct.
The vagina is formed by the mesodermal layer. So, option C is incorrect.
The retina is formed by the endoderm layer. So, option D is incorrect.
The adrenal medulla is an internal structure. It is formed by endodermis. So, option A is incorrect.

In the endodermal layer, cells migrating inward along the archenteron form the inner layer of the gastrula, which develops into the endoderm. The ectoderm is a germ layer, or tissue layer, that forms in an adult body. It is generally present in an embryo during development.

Hence, the correct answer is option (B).

Note: The endodermal layer covers the organ present inside our body. As the name suggests, the ectoderm is the germ layer that covers the outside of the embryo ('ecto' meaning outside). The ectoderm then goes on to give rise to a number of both internal and external structures. The 3 germ layers - the ectoderm, the mesoderm, and the endoderm occur or start forming during the installation phase.