mon·o·mor·phic 
(mŏn′ō-môrfĭk) also mon·o·mor·phous (-fəs)
(mŏn′ō-môrfĭk) also mon·o·mor·phous (-fəs)adj.
1. Chemistry Having only one form, as one crystal form.
2. Biology Having or existing in only one form, as having only one allele of a gene or having males and females that look alike.
mon′o·morphism n.