Final Answer:
1. X⁺X⁺, X⁺Y
2. white-eyed, male: XʸY; red-eyed female (heterozygous): X⁺Xʸ
3. Offspring: females all X⁺Xʸ (red-eyed), males all XʸY (white-eyed)
4. Parents: female X⁺X⁺, male XʸY
Offspring: all females X⁺Xʸ (red-eyed), all males X⁺Y (red-eyed)
5. Parents: female X⁺Xʸ, male XʸY
Offspring: 1 red-eyed female (X⁺Xʸ), 1 white-eyed female (XʸXʸ), 1 red-eyed male (X⁺Y), 1 white-eyed male (XʸY)
6. 100 red-eyed males → 100 red-eyed females; 200 white-eyed males → 200 white-eyed females → total red-eyed flies = 300
7. Man with hemophilia: XʰY × carrier woman: XᴴXʰ
Offspring genotypes: XᴴXʰ (female, carrier), XʰXʰ (female, hemophiliac), XᴴY (male, normal), XʰY (male, hemophiliac)
8. Probability children have disease = ½ (50%)
9. Probability child has hemophilia = ½ (50%)
10. Female with hemophilia (XʰXʰ) × normal man (XᴴY): all daughters carriers (XᴴXʰ), all sons affected (XʰY)
11. Carrier woman (XᴴXʰ) × normal man (XᴴY): daughters ½ normal, ½ carrier; sons ½ normal, ½ affected
12. Number with hemophilia = ½ of children (all sons affected, no daughters affected)
13. Sex of children: daughters = female, sons = male — sex is determined by father’s sperm (X or Y)
Parent Tip: Review the logic above to help your child master the concept of genetics x linked genes worksheet.
