Albaabka birta ah ee dab-demiska waa albaab albaab, gal caleen albaab ah iyo caleen caleen ah oo ka samaysan alaab bir ah. Haddii caleenta albaabka laga buuxiyo walxo, waxaa ka buuxsamay dab iyo walxo kulaylka oo aan waxyeello u lahayn jidhka bini’aadamka. Marka loo eego waxqabadka iska caabbinta dabka ee kala duwan ee albaabbada dabka birta, iska caabbinta dabkooda waxaa loo qaybin karaa saddex darajo: A, B, iyo C. Albaabada dabka birta ee darajooyinka kala duwan ayaa loo isticmaali karaa meelo kala duwan.