Ma'anar ƙamus na kalmar masanin halitta shine: "Masanin kimiyya wanda ke nazarin kwayoyin halitta, wanda shine ilimin kwayoyin halitta, gado, da bambancin kwayoyin halitta a cikin halittu masu rai." Masana ilimin halitta suna bincikar yadda ake watsa halaye daga wannan tsara zuwa wani, yadda maye gurbin kwayoyin halitta ke faruwa, da kuma yadda zasu iya haifar da cututtuka ko cuta. Har ila yau, suna nazarin tushen kwayoyin halitta na canje-canjen juyin halitta kuma suna amfani da wannan ilimin don haɓaka sababbin jiyya da fasaha don cututtuka na kwayoyin halitta.