Amolecule that functions in maintaining and/ or reproducing life is called a what

A molecule that functions in maintaining and/or reproducing life is called the molecule of life. The four molecules of life are proteins, carbohydrates, lipids, and nucleic acids. Each of the four groups is vital for every single organism on Earth. Without any of these four molecules, a cell and organism would not be able to live. They structurally or functionally for cells and mostly they are important in both ways. 

Fossil found in strata reveal that unused body part decrease in size