In mice, the gene for tail length has two alleles. A long tail is dominant to a short tail. If a long-tailed mouse that is heterozygous mates with a short-tailed mouse, what are the chances of having offspring with short tails?
A. 100%
B. 50%
C. 75%
D. 25%
The question states that a long tail is dominant to a short tail. This means that an individual with one long tail allele (heterozygous) will have a long tail phenotype.
When a long-tailed mouse that is heterozygous (Ll) mates with a short-tailed mouse (ll), the possible genotypes of their offspring are as follows:
- 50% chance of Ll (long tail phenotype)
- 50% chance of ll (short tail phenotype)
Therefore, the chances of having offspring with short tails is 50%, which corresponds to option B.