Space, environment, weather, population increase and decreas
It all depends on the trait. If the dominant is more common that the recessive trait then it is more likely to a dominant trait in the gene pool. But if the recessive trait is more common in the gene pool then you will have a recessive trait. Does this make sense? Let me know if I'm right!
Answer:
Hormones, Cell receptor and glands
The enzyme that breaks down H2O2 is called catalase.