NEET BIOLOGY

REPRODUCTION

EMBRYONIC DEVELOPMENT

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Layers of cells on the outer surface of the gastrula
A
ectoderm
B
endoderm
C
mesoderm
D
None of the above
Explanation: 

Detailed explanation-1: -The ectoderm is the outer layer of the embryo, which gives rise to the external ectoderm (epidermis, hair, nails) and the neuroectoderm (neural crest and neural tube-brain and spinal cord), along with the lens of the eyes and the inner ear.

Detailed explanation-2: -During gastrulation, a hollow cluster of cells called a blastula reorganizes into two primary germ layers: an inner layer, called endoderm, and an outer layer, called ectoderm.

Detailed explanation-3: -Generally speaking, the ectoderm differentiates to form epithelial and neural tissues (spinal cord, peripheral nerves and brain). This includes the skin, linings of the mouth, anus, nostrils, sweat glands, hair and nails, and tooth enamel. Other types of epithelium are derived from the endoderm.

Detailed explanation-4: -The ectoderm, on the other hand, eventually forms certain “outer linings” of the body, including the epidermis (outermost skin layer) and hair. The ectoderm also is the precursor to mammary glands and the central and peripheral nervous systems.

Detailed explanation-5: -Three primary germ layers Gastrulation is a key phase in embryonic development when pluripotent stem cells differentiate into the three primordial germ layers: ectoderm, mesoderm and endoderm.

There is 1 question to complete.