The cytoplasm the single celled organism and circulatory system in the human both

The cluster of developing cells from conception until birth is called an

Asquirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of

What is the difference between a scientific hypotheses and a scientific theory?