Answer:
Cells do not generally allow such materials to go in because they are having a cell membrane outside. The cell membrane only allows the materials which are required for the growth of the cell such as water and minerals.
Answer: a. endoderm-bone
Explanation: In the context of embryonic development, bone tissue may arise from several precursor cell populations, such as the neural crest (some facial bones), lateral mesoderm (bones of the limbs, among others), and paraxial mesoderm (vertebrae and part of the skull). There is no evidence to suggest that any of the bony structures is derived from the endoderm germ layer.
