Question

By origin, brain is

• A. Ectodermal
• B. Mesodermal
• C. Endodermal
• D. Ecto-mesodermal

Answer 1

The correct option is A

Ectodermal

The correct option is A.

Explanations for the correct option:

Option A:

1. Organogenesis is the process through which the three germ layers generated during gastrulation grow into distinct organs.
2. One of the three basic germ layers created during early embryonic development is the ectoderm.
3. It is the uppermost layer, lying on top of the mesoderm, middle and endoderm, and the innermost layer.
4. The ectoderm eventually gives rise to the nervous system and sense organs, forming the outer layer of the skin.

Explanations for the incorrect options:

Option B:

The mesoderm is responsible for the construction of the skeletal system, muscular system, excretory system, circulatory system, lymphatic system, and reproductive system in the growing embryo.

Option C:

1. Endoderm is one of the germ layers, which are clumps of cells that form early in embryonic development and give rise to all organs and tissues.
2. Except sponges, all creatures go through a process called gastrulation, which involves the formation of two or three germ layers.

Option D:

1. Ectoderm is derived from the Greek words ektos, which means "outside," and derma, which means "skin."
2. Teeth are made up of ectoderm and mesoderm: the enamel comes from the mouth cavity's ectoderm, while all other tissues come from the related mesenchyme.
3. Teeth are ectomesodermal because of this.

Final answer: By origin brain is ectodermal.