Question

In domestic swine there is a dominant allele that produces a white belt around the body. Suppose a heterozygous belted pig and solid pig mate. What is the probability they will produce a solid pig? (7 pts) 1. What is the dominant trait? What is the recessive trait? Dom: Rec: 2. What letter is assigned to the dominant and recessive trait? Dom: Rec: 3. In order to be belted, what 2 GENOTYPES could the offspring have? 4. In order to be solid, what GENOTYPE must the offspring have? 5. What are the parent genotypes you are crossing? 6. What is the ratio of probability of getting a solid pig from this cross?

Answer 1

1. Dominant trait: white belt around the body. Recessive trait: solid color without a white belt.

2. Dom: W (for white belt). Rec: w (for solid color).

3. Offspring could have the genotypes Ww or ww to be belted.

4. Offspring must have the genotype ww to be solid.

5. Heterozygous belted pig: Ww. Solid pig: ww.

6. The parent genotypes are Ww (bB) and ww (bb).

The Punnett square for this cross would be:

The probability of getting a solid pig with genotype ww from this cross is 1/2 or 50%. The ratio of probability is 1:1.