A man with brown eyes and dark hairs (whose father was blue eyed),marries a woman with blue eyes and blue curly hairs (whose mother was red straight hair). They have 4 children. What is the genotype of children
1)BbRR:BbRr:bbrr:bbRR
2)BbRR:BbRr:bbRr:bbRR
3)BbRr:BbRr:BbRR:bbrr
4)BBRR:bbrr
I know blue eyes are recessive to brown, but I have no idea about the dominance/recessive relationship for straight/curly, dark/red hair.
To determine the genotypes of the children, we need to first understand the principles of Mendelian inheritance. In this case, we are looking at several traits: eye color and hair texture. Eye color is determined by a single gene, where brown eyes are dominant (B) and blue eyes are recessive (b). Hair texture is also determined by a single gene, where curly hair (R) is dominant and straight hair (r) is recessive.
Let's analyze each child's genotype:
1) BbRR:BbRr:bbrr:bbRR
For the first child, their genotype is BbRR. This means they have one brown eye allele (B) from the father and one blue eye allele (b) from the mother. They have two copies of the curly hair allele (RR) from both parents.
2) BbRR:BbRr:bbRr:bbRR
The second child has the same genotype as the first child, BbRR. They inherited one brown eye allele (B) from the father and one blue eye allele (b) from the mother. They also have two copies of the curly hair allele (RR) from both parents.
3) BbRr:BbRr:BbRR:bbrr
For the third child, their genotype is BbRr. They have one brown eye allele (B) from the father and one blue eye allele (b) from the mother. They have one copy of the curly hair allele (R) and one copy of the straight hair allele (r) for hair texture.
4) BBRR:bbrr
The fourth child has a different genotype. They inherited two copies of the brown eye allele (BB) from the father and two copies of the curly hair allele (RR) from both parents.
To summarize:
1) BbRR
2) BbRR
3) BbRr
4) BBRR