Within any ecosystem, there is a fixed amount of energy available for organisms to use. since organisms usually produce more offspring than a given ecosystem can support, this causes

Competition

For organisms are going to fight for the limited food or resource

cell differentiation  is how generic embryonic  cells  become specialized  cells. this occurs  through a process called gene expression. gene expression is the specific combination of genes that are turned on or off (expressed or repressed), and this is what dictates how a  cell  functions.

explanation:

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it