No; many things in biology are not easily defined (due to limitations of technology, or our own ability to classify things is faulty) but are solidly in the are

No; many things in biology are not easily defined (due to limitations of technology, or our own ability to classify things is faulty) but are solidly in the area of quantitative biology. Example: in the past, "rho factor" was a magical component in a test tube that had a well-defined activity but nobody knew "what" rho was (hence the term "factor"). Eventually, rho factor was isolated and purified to the point where molecular characterization determined it was a protein with a specific function. but that didn't stop people from studying it as a "thing" that had no real "definition" other than the visible activity of its function.