In cattle the allele for cloven hooves (H) is dominant over the allele for mule-foot hooves (h). The phenotype for each trait is shown in this picture.

Question

What is the probability of cloven hooves in the offspring of parents that are heterozygous for the trait?
25%
50%
75%
100%

Answer 1

To determine the probability of cloven hooves in the offspring of parents that are heterozygous for the trait (Hh x Hh), we can use a Punnett square.

1. Set up the Punnett square with one parent's alleles on the top and the other parent's on the side:

        H     h
      __________
    H |  HH  |  Hh  |
      |______|______|
    h |  Hh  |  hh  |
      |______|______|

2. From the Punnett square, we can see the possible genotypes of the offspring:

   • HH (homozygous dominant) - cloven hooves
   • Hh (heterozygous) - cloven hooves
   • Hh (heterozygous) - cloven hooves
   • hh (homozygous recessive) - mule-foot hooves

3. Now count the phenotypes:

   • 3 offspring have cloven hooves (HH, Hh, Hh)
   • 1 offspring has mule-foot hooves (hh)

The ratio of cloven hooves to total phenotypes is 3:4.

So, the probability of getting cloven hooves in the offspring is:

\[ \frac{3}{4} = 75% \]

Thus, the answer is 75%.