How do limiting factors in an ecosystem help keep the ecosystem balanced?

Adigestive system that is a series of tubes beginning at the mouth and ending at the anus is a digestive system.

The idea of spontaneous generation was disproved by in a experiment involving jars of meat

Which best describes the nucleus of an atom a. it is where all of the particle s of the atom are located b. it is the negatively charged part of the atom c. it is where the electrons and the protons are located d. it is the part of the atom with the greatest mass