The main difference between stream pools and ponds is that stream pools

Ponds and lakes are inland bodies of water that can be either natural or manmade. Lakes are typically larger than ponds and are fed by rivers. Stream pools are a part of a river or creek where the movement of water is slower and there is a greater water depth.

I’m not exactly sure what your trying to ask, but if it’s how an organelle is similar to a body system or a part a nucleus is like a in function. but i don’t fully understand what you’re trying to ask