Answer;
Ectoderm
During gastrulation in frogs, cells from the animal pole spread over the embryo and form the ectoderm.
Step-by-step explanation;
- Gatrulation is when the three germ layers form around the embryo in preparation for the next step of embryogenesis, that is organogenesis. The three germ layers namely; ectoderm, endonderm and mesoderm are the basis of all the organs that will form after this stage.
- Ectoderm is the outermost layer, which later froms may different lining such as the outer layer of the skin, esophagus, and many other organs. Endoderm is the inside layer of gastrula and forms the digestive tract of the embryo. Mesoderm is the middle layer and ends up becoming the skeletal muscles of organisms as well as bones, blood, and sex organs.