In Aplocheilus, the female sex is homogametic, and the male heterogametic. A pair of R and r alleles, which determine body color

In Aplocheilus, the female sex is homogametic, and the male heterogametic. A pair of R and r alleles, which determine body color, are localized in homologous regions of the sex chromosomes. Red is dominant and white is recessive. Determine what offspring to expect from the cross:
1) two heterozygous fish;
2) a heterozygous female with a homozygous red male;
3) a white female with a heterozygous male.

1) In F1, red females, red males and white males in a ratio of 2: 1: 1;
2) in F1, red females and red males in a 1: 1 ratio;
3) a) if in a male the dominant gene is localized in the Y chromosome, and the recessive gene in the X chromosome, then in F1 red females and white males in a ratio of 1: 1; b) if in a male the dominant gene is localized in the X chromosome, and the recessive gene in the Y chromosome, then in F1 there are white females and red males in a 1: 1 ratio.

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