Which is a part of the cell theory?

cells come from pre-existing cells

cells have a nucleus

organisms with one cell must be seen with a microscope

organisms must have more than one cell to live

A - cells come from pre-existing cells. Cell theory is the thought that cells split from one to create a new cell. Therefore cells come from a pre-existing cell.

relationships play a major role in a human's emotional and mental wellbeing. healthy relationships with the people around you are even linked to a smaller production of cortisol, a stress hormone.

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.