Explanation: Central nervous system originates from ectoderm, neuroectoderm gives rise to neural tube, the primordia of brain and spinal cord. Neural tube is the embryonic structure, neural plate folds into neural tube is formed at the dorsal side of embryo.
The Calvin cycle of photosynthesis starts when the energy of light is processed to chemical energy within the cells of plants. The ATP molecules created power the Calvin cycle. The Calvin cycle utilizes energy to create carbohydrates from h20 and co2.