Question

Draw and label each of the stages indicated below, and answer the following questions. Gastrulae (Label gastrula, archenteron, endoderm, ectoderm, blastocoel) m) What is the fate of the pore that has formed by the invagination of gastrulation?

Answer 1

Ans1:

Ans2:

During gastrulation, cell movements result in a massive reorganization of the embryo from a simple spherical ball of cells, the blastula, into a multi-layered organism. During gastrulation, many of the cells at or near the surface of the embryo move to a new, more interior location.

The primary germ layers (endoderm, mesoderm, and ectoderm) are formed and organized in their proper locations during gastrulation. Endoderm, the most internal germ layer, forms the lining of the gut and other internal organs. Ectoderm, the most exterior germ layer, forms skin, brain, the nervous system, and other external tissues. Mesoderm, the the middle germ layer, forms muscle, the skeletal system, and the circulatory system.

Ans3

rchenteron A primitive digestive cavity of the embryo at the gastrula stage of development in animals. It is formed by invagination of mesoderm and endoderm cells, opens to the outside by a blastopore, and finally develops into the gut cavity.

Ans4

The formation of this blastocoel begins when the early dividing cells of the recently fertilized egg begin to differentiate. This is when they become specialized, as they move around and start to form a new space where there used to be solid cells. These changes, and the presence of the blastocoel, mark the blastula stage of development, which in mammals is called a blastocyst.