Answer:
Stem cells are cells with the potential to develop into many different types of cells in the body. They serve as a repair system for the body. There are two main types of stem cells: embryonic stem cells and adult stem cells
Explanation:
Totipotent (or Omnipotent) Stem Cells.
Pluripotent Stem Cells.
Multipotent Stem Cells.
Oligopotent Stem Cells.
Unipotent Stem Cells.
Other reasons are
Not finishing the antibiotics.
Or
Taking antibiotics too often
This is the Definition of coevolution
Organisms on earth live in the Biosphere