Because the oxygen produced in photosynthesis is used in respiration, and the carbon dioxide produced in respiration is used in photosynthesis.
Answer:
long cold winters, with annual temperatures mostly below freezing.
One dominant and one recessive for each parent is what you were asking for right ?
It is one of the most powerful mood-altering chemicals. It was discovered in 1938 and is made from lysergic acid, which is found in ergot, a fungus that grows on rye and other grains.
