why the mother can’t be heterozygous?

well, you could come up with some mutation or gene expression alteration… but that had to occur already in mother’s ovaries or what do flies have, as all offspring is the same

Yes, the only way apart from mutations, would be a heterozygous mother since the male has only a recessive r, and the female must have another recessive r (as a female offspring has rr=red eyes), thus, the genotype of the mother must be Rr or else there will be no recessive phenotyped children. (add punnet square here)

Hi, maybe there is problem with cultivation temperature. There has been one experiment in Swiss, where drosophila eggs were cultivated in different temperature and the color of their eyes has changed.

Can anyone explain me the problem of red eyes and white eyes

yeah, I think some silencing… however, question is, whether it would occur in all females?

JackBean: Sa mi zda ze tam sa jednalo o epigeneticku zmenu. A nepamatam sa, zeby hovorili o nejakych pomeroch, ale skor, ze sa to stalo u vsetkych.

však jo, silencing je epigenetická změna způsobená třeba methylací, ať už v promotoru nebo v kódující oblasti.

A pokud to bylo dáno podmínkami, tak je logické, že toho dosáhli u všech. Jenže to nevysvětluje, proč chlapáci měli červený oči 😉