Based on the clue 'because they are never found in chemical compounds...', what is the answer?

Based on the clue 'because the shorter blue light waves are scattered...', what is the answer? Based on the clue 'because the yoke originally was cut off the name o...', what is the answer? Based on the clue 'because there are no blood vessels in this layer o...', what is the answer? Based on the clue 'because these baby birds feed from their parents p...', what is the answer? Based on the clue 'because they cant digest cellulose pandas may eat ...', what is the answer? Based on the clue 'because they develop from a single ovum this varie...', what is the answer? Based on the clue 'because they excrete fluid outside the body sweat ...', what is the answer? Based on the clue 'because they fit one inside the other russian matr...', what is the answer?