In Greece, if a man called Papadopoulos has a daughter or wife, she will likely be named Papadopoulou, the genitive form, as if the daughter/wife is "of" a man named Papadopoulos. Likewise, the surnames of daughters and wives of males with surnames ending in -as will end in -a, and those of daughters and wives of males with the -is suffix will have the -i suffix.
In Greece, if a man called Papadopoulos has a daughter or wife, she will likely be named Papadopoulou, the genitive form, as if the daughter/wife is "of" a man named Papadopoulos. Likewise, the surnames of daughters and wives of males with surnames ending in -as will end in -a, and those of daughters and wives of males with the -is suffix will have the -i suffix.