NEET BIOLOGY

Detailed explanation-1: -Endoderm is the innermost of the three primary germ layers in the very early embryo. The other two layers are the ectoderm (outside layer) and mesoderm (middle layer). Cells migrating inward along the archenteron form the inner layer of the gastrula, which develops into the endoderm.

Detailed explanation-2: -Gastrulation is characterized by cell movement and reorganization within the embryo (morphogenetic movements) to the interior of the embryo, forming three primary germ layers: ectoderm, mesoderm, and endoderm. the mesoderm lies between these two layers.

Detailed explanation-3: -The endoderm is the innermost germ layer that forms the linings of the respiratory and gastrointestinal tracts, and their associated organs, during embryonic development.

Detailed explanation-4: -Endoderm forms the epithelium-a type of tissue in which the cells are tightly linked together to form sheets-that lines the primitive gut. From this epithelial lining of the primitive gut, organs like the digestive tract, liver, pancreas, and lungs develop.

Detailed explanation-5: -The process of gastrulation generates the three primary germ layers (ectoderm, endoderm, mesoderm), which primes the system for organogenesis and is one of the most critical steps of development.