Question

Adrenal medulla and labyrinth develops from
(a) Ectoderm
(b) Endoderm
(c) Mesoderm
(d) Both B and C

Answer 1

Hint: Adrenal Medulla and labyrinth membranous develop from the tissue layer which is formed in an animal during embryonic development. This tissue layer is common in both diploblastic and triploblastic animals and covers the outside of the embryo.

Complete answer:
The ectoderm is a germ layer that forms during embryonic development. Since it covers the outer side of the embryo it is called ectoderm (“ecto” means outside). Ectoderm forms during the gastrulation when the embryo undergoes cleavage. The cells that are in the upper layer of the embryo form the ectoderm and other cells form the consecutive layers.
The following are formed from the ectoderm:
-Epidermis
-Cutaneous glands
-Nervous system (Brain and Spinal cord)
-Eye (Retina, lens, and cornea)
-Nasal epithelium
-Internal and External ear
-Lateral line sense organs
-Stomodaeum
-Proctodaeum
-Pituitary gland
-Pineal gland
-Adrenal medulla

Additional Information: -Gastrulation is characterized by the movement of cells in small masses or sheets to form primary germinal layers.
-There are three primary germinal layers: Endoderm, Ectoderm, and Mesoderm.
-A space appears between the ectoderm and trophoblast. This is known as the amniotic cavity, filled with amniotic fluids. The roof of this cavity is formed by amnio genic cells derived from the trophoblast.
-The cells of the inner cell mass or embryonal knob get rearranged to form a flat embryonic or germinal disc. The latter differentiates into two layers, an outer epiblast of large columnar cells and an inner hypoblast of small cuboidal cells.
-The membranous labyrinth is a tube filled with fluid that contains the receptors for hearing and also senses the equilibrium.
-Adrenal medulla is the inner part of the suprarenal gland which controls the hormones for flight, fright, or fight i.e. adrenaline and noradrenaline.
So, the correct answer is, “Ectoderm.”

Note: -The cell movements that occur during gastrulation are called morphogenetic movements since they lead to the initiation of morphogenesis.
-After the process of gastrulation, the product is no longer known as a zygote. It is called a gastrula.
-Remaining epiblast cells from the ectoderm. Thus, the epiblast is the source of all the germ layers
in the embryo as it also forms endoderm and mesoderm.
-Primitive streak marks the beginning of the gastrulation on the surface of the epiblast which becomes a notochordal sheath that forms the vertebral column.
-Only the adrenal medulla is formed from ectoderm. The adrenal cortex is formed from the mesoderm.