Growth and Reproduction

Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field

Growth and Reproduction. Living things grow and they reproduce. Growth is a way to generate the materials for reproduction. Reproduction is a way to make new organisms that can grow. Thus, the apparent "goal" of every organism is to fill the available world with its offspring, that is, with "self".