Which organ do stem cells start differentiating to form a few weeks after conception?

What evidence supports the law of conservation of energy? a) mechanical energy is converted to chemical energy during photosynthesis. b) oxygen is made from the breakdown of carbon dioxide during photosynthesis. c)energy is absorbed by chlorophyll and becomes chemical energy during photosynthesis. d)the sun gives off light energy that is absorbed by plants.

Which would be the most useful source of evidence to support mcneill's contention?

Wich level of organization includes all the other levels or organizations