Biology is simply the study of life. Being such a broad subject it has naturally been divide into many subdisciplines including Ecology, Genetics, Molecular Biology, Zoology, and Botany.
Biology began as an interest in life with the first original subdisciplines being Zoology (the study of animals) and Botany (the study of plants). From there we learned that life wasn't so simple as just plants and animals. We discovered that plants and animals were made of cells and small single-celled organisms, which beget the fields of Molecular and Cellular Biology. We learned that DNA contained the building blocks of life and what that means for the existence of life, and this begets Genetics.
We also learned that life exists in its environment and that environment has a large effect on life and thus the field of Ecology came into being.
From there many subdisciplines, within each of these disciplines came into being as we discovered how complex life truly is. These fields are constantly expanding to this day and beyond.
Biology began as an interest in life with the first original subdisciplines being Zoology (the study of animals) and Botany (the study of plants). From there we learned that life wasn't so simple as just plants and animals. We discovered that plants and animals were made of cells and small single-celled organisms, which beget the fields of Molecular and Cellular Biology. We learned that DNA contained the building blocks of life and what that means for the existence of life, and this begets Genetics.
We also learned that life exists in its environment and that environment has a large effect on life and thus the field of Ecology came into being.
From there many subdisciplines, within each of these disciplines came into being as we discovered how complex life truly is. These fields are constantly expanding to this day and beyond.