Assuming if height was fully determined genetically, what would be the concordance between monozygotic pairs? I fully understand the differences between monozygotic and dyzogtic twin pairings, but I wondered how I could put into words the reasons why the concordance would be very high. * Derived from same zygote, so precisely the same genetic material from mother and father. Would this suffice as a scientific answer?

If height was fully determined genetically (and no trait is), then concordance between monozygotic pairs would be almost perfect, modulo some variation due to somatic mutation in early development (e.g. a mutation happens in in cell directly after the embryo splits).