Question

The archenteron develops into

(A) the mesoderm.

(B) the endoderm.

(C) the placenta.

(D) the lumen of the digestive tract.

Short answer

(A)The option “the mesoderm” is incorrect.

(B)The option “the endoderm” is incorrect.

(C)The option “the placenta” is incorrect.

(D)The option “the lumen of the digestive tract” is correct.

Step-by-step solution

Archenteron

In mammals, the gastrula stage of development is characterized by a rudimentary digestive chamber in the embryo. It is created by the invasion of mesoderm and endoderm cells into the gut cavity, which is then opened from the outside by a blastopore.

Explanation of option ‘(A)’

The mesoderm develops from the middle layer of the three germ layers during gastrulation. The mesoderm further forms muscles by a process called myogenesis. The mesoderm differentiates in the embryo by the intracellular signaling pathways.

Thus, archenteron does not develop into mesoderm.

Therefore, the given option is incorrect.

Explanation of option ‘(B)’

The ingression of the primitive streak and replacing the hypoblast cells form the definite endoderm. The endoderm is the outer layer of the three germ layers. The endoderm also forms the epithelium tissue and organs like the primitive gut, liver, pancreas, and lungs.

Thus, archenteron does not develop into endoderm.

Therefore, the given option is incorrect.

Explanation of option ‘(C)’

The outer cell line grows into the uterus during gastrulation and develops a placenta in a growing embryo. This outer layer is called the trophectoderm. The placenta is a connecting tube-like structure between the embryo and the mother.

Thus, the archenteron does not develop into the placenta.

Therefore, the given option is incorrect.

Explanation of option ‘(D)’

The archenteron is identified explicitly for its development into the digestive tract cavity. The primitive gut cavity or archenteron gives rise to a hollow opening or lumen called the alimentary canal.

Thus, the archenteron develops into the lumen of the digestive tract.

Therefore, the given option is correct.