The most accepted theory regarding the make-up of living things is the cell theory.
Explanation;
-Cell theory is a theory that includes one or both of the statements that the cell is the fundamental structural and functional unit of living matter and that the organism is composed of autonomous cells with its properties being the sum of those of its cells.
-According to cell theory; All living beings are made up of cells. Cell is the most basic unit of life. All cells must come from pre-existing cells.
-Cells are autonomous, in that they can acquire and use nutrients to obtain energy and they can reproduce. Simple organisms like bacteria are unicellular and composed of a single cell.
Reaches the adult stage is the correct answer. When an intervebrate reaches the adult stage it has most likely stopped growing and can finally begin reproduction, passing further down the line his genes and the genes of his ancestors.
