That is false. Ecology is the study of relations of organisms to one another and to their physical surroundings. Cell biology is the study of cells and their functions.
Yes, They all are! They all can be the start of something.
The answer would be : <span>It is a well supported explanation which cannot become a law.
A law and a theory are different you know. In fact, the law is universel. This applies for everything unlike a theory which explains in particular why something is happening.
Any doubts ?
Hope this helps !
Photon</span>