To determine the chances of having offspring with short tails when a heterozygous long-tailed mouse (genotype Ll) mates with a short-tailed mouse (genotype ll), we can set up a simple Punnett square.
- Parent 1 (long-tailed, heterozygous): Ll
- Parent 2 (short-tailed, homozygous recessive): ll
The possible combinations for their offspring would be:
| | L | l | |------|-----|-----| | l | Ll | ll | | l | Ll | ll |
From the Punnett square, we can see the potential genotypes of the offspring:
- 50% Ll (long-tailed)
- 50% ll (short-tailed)
Thus, the chances of having offspring with short tails (ll) is 50%.
So the correct answer is 50%.