To determine whether a guinea pig with black fur is heterozygous (Bb) or homozygous (BB), you need to follow a specific breeding strategy. Let’s go through the detailed steps to identify the correct method:
1. Understanding Genotypes and Phenotypes:
- BB genotype results in black fur.
- Bb genotype also results in black fur.
- bb genotype results in white fur.
2. Parent Genotype Combinations:
- If the black-fur guinea pig is BB and we breed it with a white-fur guinea pig (bb):
- The possible offspring genotypes are: [tex]\( BB \times bb \Rightarrow Bb \quad (all offspring will have black fur).\)[/tex]
- If the black-fur guinea pig is Bb and we breed it with a white-fur guinea pig (bb):
- The possible offspring genotypes are: [tex]\( Bb \times bb \Rightarrow Bb \; (black fur) \;\; \& \;\; bb \; (white fur) \quad (in a 1:1 ratio).\)[/tex]
3. Breeding Strategy:
- To determine if the black-fur guinea pig is heterozygous (Bb) or homozygous (BB), you should breed it with a guinea pig that has white fur (bb).
4. Observation Analysis:
- If all offspring have black fur (Bb), then the black-fur parent is homozygous (BB).
- If any offspring have white fur (bb), then the black-fur parent is heterozygous (Bb).
Therefore, the correct approach is:
Breed the guinea pig with another guinea pig that has white fur and check the coloring of each new guinea pig.
