Answer:
The hamsters were all brown because one side gave all dominant genes.
Step-by-step explanation:
In the question, it tells you that one group of hamsters all had the genotypes BB. The other group had the genotype bb. In biology, capital letters represent dominant traits and lowercase represent recessive traits. Using this knowledge, we now know that one hamster has all dominant genes, while the other had all recessive genes. In this example, we will only need to use one law of inheritance: the law of dominance. In the law of dominance, if an individual inherits two different alleles (B & b) and only one phenotype is visible (the brown of B), then that allele is dominant. That explains why the hamsters are all brown! Each hamster has one dominant allele that came from the hamster that had BB. Now, you might wonder where the Punnett Square ties into this. A Punnett square is used to track the alleles of organisms. If you draw a Punnett square, you'll be able to see that each box has Bb inside of it. This means that each hamster offspring carries one dominant and one recessive gene inside of it. While they all have a b, the dominant B gene is also there, so the hamsters are all brown. I'm sorry this is so wordy, but I hope this helps!