THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -Gastrulation leads to the formation of the three germ layers that give rise during further development to the different organs in the animal body. This process is called organogenesis. Organs develop from the germ layers through the process of differentiation.

Detailed explanation-2: -These changes are due to alterations in the set of genes expressed in the cells. Eventually, the cells of the embryo are split into three different groups known as germ layers: mesoderm, endoderm, and ectoderm. Each germ layer will, under normal conditions, give rise to its own specific set of tissues and organs.

Detailed explanation-3: -Organogenesis is the phase of embryonic development that starts at the end of gastrulation and continues until birth. During organogenesis, the three germ layers formed from gastrulation (the ectoderm, endoderm, and mesoderm) form the internal organs of the organism.