One difference is that some animals are polyp and some are medusa.
The other difference is that some animals have medusa in their life or polp in their life cycle.
Hope these two differences helps :D
Answer:
Option B : burning of wood
Explanation:
Chemical change is a change where a new substance is created like when you will bur wood you get ash this is a new substance, so burning of wood is a chemical change.
Fe(s) + CuSO4(aq) -> Cu(s) + FeSO4(aq) is the answer if you get it in advance...