The oxygen released by plants comes from what reactant in photosynthesis?

What are the four basic classes of organic molecules how do they differ structurally and functionally

Many farmers prefer cattle without horns because it is safer for their herds. the allele for no horns (n) is dominant to the allele for the presence of horns (n). a farmer mates a male with horns to a heterozygous female without horns. what is the chance that the offspring will have horns?

Guard cells control which event? the growth of plants capture of solar energy gas exchange in leaves water absorption in roots