Question

The main function of the trophectoderm is mammalian embryo is
A.Protection of the developing cells
B.Drawing food for the developing cells
C.Formation of yolk sac.
D.Formation of body of developing embryo

Answer 1

Hint: The outermost layer of cells in the mammalian blastodermic vesicle is called the trophectoderm. It gives rise to chorion. The epiblast which is the inner cell develops the proper embryo.

Complete answer:
-The mother provides oxygen and nutrients to the embryo through the placenta. It also provides protection to the embryo by sending antibodies via the placenta.
-Trophectoderm comes in contact with the endometrium and helps the embryo to receive its nutrition. It draws a connection between the mother and the fetus by forming the placenta.
-Hypoblast endoderm and extraembryonic mesoderm forms the yolk sac. Pinocytosis is the process through which the yolk sac takes in nutrients. The nutrients are then stored in the form of storage vesicles.
-The cells present in the blastula reposition themselves spatially in order to form three different layers of cells. This is termed as gastrulation. Muscle cells and connective tissues are formed by the mesoderm.
Hence, option B: Drawing food for the developing cells is the correct answer.

Note: As the morula develops into a blastocyst, the trophectoderm develops concurrently with blastocoele fluid development. A trophectoderm contributes to placenta formation and thus forms a bridge between the mother and the fetus. The transmission of food and nutrients from the mother to the fetus helps.