Reference no: EM132561161

1. Write the cross

2. Allele key

3. Punnett Square

4. Genotype Ratio

5. Phenotype Ratio

1. Cross a heterozygous brown hamster and a homozygous white hamster. Brown is the dominant allele.

2. A man with no freckles marries a woman with freckles. The allele for freckles is dominant yet they produce a son with no freckles. Show the cross. Why does this happen?

3. A homozygous red 4 o'clock flower is crossed with a heterozygous pink 4 o'clock flower. Incomplete dominance is displayed.

4. Two homozygous pea plants, one producing round dominant peas and the other wrinkled recessive peas are crossed. Show the predicted F1 and F2 results.

5. A series of tall and short tomato plants are grown and found to number in a ratio of 3:1, or 3 tall to 1 short. Show the parents of this cross and probable genotypes of the offspring.

6. In Andalusian chickens there is co-dominance between genes for black (B) and white (W) feather color. A bluish hybrid, or heterozygote, is produced. Show the results from crossing 2 bluish hybrid chickens.

7. John and Mary get married and decide that they want to have children. John has blood type A, and Mary has blood type O. Cross John and Mary using a possible genotype for each. Show the genotypes, phenotypes, and ratios for their children.

8. John and Mary had a child. It turns out that the baby is blood type O, just like Mary. They name their baby boy Luke. Luke marries Jane. Jane has blood type AB. Do a cross for Luke and Jane and determine what their children's blood types may be.

Sex-linked Inheritance Problems:

9. A human female "carrier" who is heterozygous for the recessive, sex-linked trait causing hemophilia, marries a hemophiliac male. The couple would like to have children, but are concerned about passing this trait on to their offspring. Do the cross, then explain to the couple if they are at risk for having hemophiliac children, and why or why not?

10. A human female "carrier" who is heterozygous for the recessive, sex-linked trait red color blindness marries a normal male. Do the cross and indicate what proportion of the male and female offspring will show the trait.