If the emergent property is novel and emergent properties are, then it has something about it that is neither found nor described by any level below it.
Actually in many cases the issue is merely about complexity and scale. Single cells have most of the basic functions of larger physiological units (e.g. tissues, organs etc) - e.g. energy metabolism, excitation properties, structural features, transport processes, ability to replicate, features associated with motility etc etc. When cells come together to form tissues and beyond you add complexity as you can create networks, but also you permit scale. A single cell is about 50 times smaller than one millimetre - that isn't going to hack it to generate the functionality of a 1.8 metre person. You are going to need lots of cells, which is indeed what you have.
But I think you need to define what you mean by emergent and place it in the context of animal physiology. Once you've done that then I can address whether the property you describe is truly emergent or merely replicated at tissue/organ level with greater complexity and scale.