Question

Ectoderm gives rise to
A. Cornea, heart, bronchi, dentine
B. Adrenal cortex, tongue, liver, retina
C. Lungs, adrenal medulla, dermis, thyroid
D. Enamel of teeth, nails, adrenal medulla, hair

Answer 1

Hint: Ectoderm is a germ layer, or tissue layer, which is formed in an animal embryo during developmental stage. It is one of the three primary germ layers which is formed during early embryonic development. The germ layer that covers the outside of the embryo is Ectoderm; as the name itself suggests. A number of both internal and external structures rise from Ectoderm.

Complete answer:
Option A) Cornea, heart, bronchi, dentine: Surface of ectoderm develops into cornea. Heart and spleen are developed by the lateral plate mesoderm with the whole circulatory system. Dentine of teeth is formed from mesoderm. Bronchi is developed by endoderm.
Since all these are developed by different germ layers, option A is not correct.
Option B) Adrenal cortex, tongue, liver, retina: Both Adrenal cortex and tongue are developed from mesoderm. Endoderm forms the liver. Retina is developed by ectoderm.
Since all developments of this option are from different germ layers, option B is also not correct.
Option C) Lungs, adrenal medulla, dermis, thyroid: In here, both lungs and thyroid are developed from endoderm. The neural crest of the ectoderm develops into adrenal medulla. Dermis is developed by paraxial mesoderm.
Hence option C is also not correct.
Option D) Enamel of teeth, nails, adrenal medulla, hair: All of these are developed from ectoderm germ layer. The surface ectoderm develops into enamel of teeth, nails and hair. Neural crest of the ectoderm develops into adrenal medulla.
Hence option D is the correct answer.

Therefore, Option D. Enamel of teeth, nails, adrenal medulla, hair is the correct answer.

Note:
The outer layer of the embryo is generated from ectoderm, and it forms from the embryo's epiblast. The ectoderm germ layer further develops into three layers: surface ectoderm, neural crest, and neural tube. The neural crest is sometimes considered as the fourth germ layer because of its great importance. However, it is derived from the ectoderm germ layer.