Yes the o horizon layer is where most plant life is like in a forest it where all the roots of grass is
I just looked it up, it's carbon!
The main difference between sexual and asexual reproduction is whether it has one or two parents. Sexual reproduction involves two parents and asexual involves one.
Another is that a large number of progenies are produced with asexual reproduction but a limited number of progenies are produced with sexual.
Answer:
Oxygen liberated during photosynthesis comes from the splitting or hydrolysis of water in the green plants. Cornelius van Niel experimentally proved for the first time that the oxygen liberated during photosynthesis comes from water and not from carbon dioxide.