When solving this problem, we need to consider the principles of Mendelian genetics and understand how these traits are inherited. Here, we are dealing with two traits: body color and eye color. Each trait has two alleles, one dominant and one recessive.
1. Body Color:
- Brown body color (B) is dominant.
- Black body color (b) is recessive.
2. Eye Color:
- Red eye color (R) is dominant.
- Brown eye color (r) is recessive.
Since the parents are heterozygous for both traits, their genotypes are both BbRr. When two heterozygous individuals are crossed, we can use a Punnett square to determine the possible genotypes of the offspring.
We'll use a 4x4 Punnett square to list all possible combinations of alleles for both traits.
Constructing the Punnett Square:
Parents' genotypes:
[tex]\[BbRr \times BbRr\][/tex]
The gametes they can produce (B can pair with R/r and b can pair with R/r):
[tex]\[BR, Br, bR, br\][/tex]
We will cross each gamete combination using the Punnett square:
[tex]\[
\begin{array}{c|c|c|c|c}
& BR & Br & bR & br \\
\hline
BR & BBRR & BBRr & BbRR & BbRr \\
\hline
Br & BBRr & BBrr & BbRr & Bbrr \\
\hline
bR & BbRR & BbRr & bbRR & bbRr \\
\hline
br & BbRr & Bbrr & bbRr & bbrr \\
\end{array}
\][/tex]
List of all possible genotypes and their counts:
- BBRR, BBRr, BbRR, BbRr, BBrr, Bbrr, bbRR, bbRr, bbrr
Let's number the offspring and list the possible genotypes:
1. BBRR
- Homozygous dominant for both traits
2. BBRr
- Homozygous dominant for body color and heterozygous for eye color
3. BbRR
- Heterozygous for body color and homozygous dominant for eye color
4. BbRr
- Heterozygous for both traits
5. BBrr
- Homozygous dominant for body color and homozygous recessive for eye color
6. Bbrr
- Heterozygous for body color and homozygous recessive for eye color
7. bbRR
- Homozygous recessive for body color and homozygous dominant for eye color
8. bbRr
- Homozygous recessive for body color and heterozygous for eye color
Thus, the possible genotypes for offspring 1-8 would be:
1. BBRR
2. BBRr
3. BbRR
4. BbRr
5. BBrr
6. Bbrr
7. bbRR
8. bbRr
