  The question whether Quantum Mechanics describes all aspects of both the
micro-world of elementary particles and living organisms adequately is still
open. A Bell inequality test without locality and detection loopholes will
deliver the answer when applied to macroscopic systems. Here we show that an
experimentally feasible loophole-free Bell test is possible using only
multi-photon polarization entanglement and linear optics. We apply a
preselection protocol which produces genuine macroscopic superpositions and
entanglement, thus eliminating postselection and dark counts. Such
superpositions are usually difficult to generate. Their study paves the way for
testing the quantum nature of biological organisms such as plants, viruses and
human brain. Our results find application in creating quantum superpositions of
living organisms and their manipulation.
