1. Practice with punnett squares

2. In dolphins, the allele for blue eyes is dominant over the allele for brown eyes. Cross two homozygous dominant parents.
Show the parental cross.
Show the Punnett square.
List all of the possible genotypes and their probabilities (as a fraction and as a percent).
List all of the possible phenotypes and their probabilities (as a fraction and as a percent).

3. A certain fatal disease gene is recessive to the healthy gene
A certain fatal disease gene is recessive to the healthy gene. It is a common disease in certain ethnic groups. A woman knows that she is a carrier for the disease. This means she is heterozygous. She marries a man that is also a carrier for the disease.
Show the parental cross.
Show the Punnett square.
List all of the possible genotypes and their probabilities (as a fraction and as a percent).
List all of the possible phenotypes and their probabilities (as a fraction and as a percent).

4. In fruit flies, long wings (L) is dominant to short wings (l)
In fruit flies, long wings (L) is dominant to short wings (l). Cross two homozygous recessive parents.
Show the parental cross.
Show the Punnett square.
List all of the possible genotypes and their probabilities (as a fraction and as a percent).
List all of the possible phenotypes and their probabilities (as a fraction and as a percent).

5. In pea plants, the allele for smooth pods (P) is dominant over the allele for pinched pods (p). Cross a homozygous dominant parent with a heterozygous parent.
Show the parental cross.
Show the Punnett square.
List all of the possible genotypes and their probabilities (as a fraction and as a percent).
List all of the possible phenotypes and their probabilities (as a fraction and as a percent).

6. In a certain animal, long tails are dominant to short tails
In a certain animal, long tails are dominant to short tails. Cross a short-tailed animal with a heterozygous long-tailed animal.
Show the parental cross.
Show the Punnett square.
List all of the possible genotypes and their probabilities (as a fraction and as a percent).
List all of the possible phenotypes and their probabilities (as a fraction and as a percent).

7. In dogs, wire-haired fur is dominant to smooth fur
In dogs, wire-haired fur is dominant to smooth fur. Cross a homozygous wire-haired with a smooth haired dog.
Show the parental cross.
Show the Punnett square.
List all of the possible genotypes and their probabilities (as a fraction and as a percent).
List all of the possible phenotypes and their probabilities (as a fraction and as a percent).

8. In pea plants, purple flowers are dominant to white flowers
In pea plants, purple flowers are dominant to white flowers. Cross two homozygous dominant parents.
Show the parental cross.
Show the Punnett square.
List all of the possible genotypes and their probabilities (as a fraction and as a percent).
List all of the possible phenotypes and their probabilities (as a fraction and as a percent).

9. In a place called Troublesome Creek, Kentucky, there is a population of people who are blue. It is a rare but recessive condition. It is more frequent in this population because for many years this was an isolated area where people intermarried. Cousins married cousins so the chances of having two recessive genes was greater. In the early 1800’s, Martin Fugate married Mary. They were carriers- both were heterozygous for the blue trait. In a cross between these two heterozygous parents, what is the probability that their offspring will be normal (N, dominant) or blue (n, recessive)
Show the parental cross.
Show the Punnett square.
List all of the possible genotypes and their probabilities (as a fraction and as a percent).
List all of the possible phenotypes and their probabilities (as a fraction and as a percent).

10. In guinea pigs, brown fur (B) is dominant over white fur (b)
In guinea pigs, brown fur (B) is dominant over white fur (b). Cross a homozygous dominant parent with a heterozygous parent.
Show the parental cross.
Show the Punnett square.
List all of the possible genotypes and their probabilities (as a fraction and as a percent).
List all of the possible phenotypes and their probabilities (as a fraction and as a percent).

11. In flowers, red petals (R) are dominant over white flowers (r)
In flowers, red petals (R) are dominant over white flowers (r). Cross a homozygous recessive parent with a heterozygous parent.
Show the parental cross.
Show the Punnett square.
List all of the possible genotypes and their probabilities (as a fraction and as a percent).
List all of the possible phenotypes and their probabilities (as a fraction and as a percent).

12. In humans, the ability to roll one’s tongue is common
 In humans, the ability to roll one’s tongue is common. The ability to roll is dominant to non-rolling. What are the odds that children of a homozygous male roller crossed with a non-roller will be rollers?
Show the parental cross.
Show the Punnett square.
List all of the possible genotypes and their probabilities (as a fraction and as a percent).
List all of the possible phenotypes and their probabilities (as a fraction and as a percent).

13. In rats, the allele for black fur is dominant over the allele for white fur. Cross a heterozygous parent with a homozygous recessive parent.
Show the parental cross.
Show the Punnett square.
List all of the possible genotypes and their probabilities (as a fraction and as a percent).
List all of the possible phenotypes and their probabilities (as a fraction and as a percent).

14. In humans, free earlobes are dominant over attached earlobes
In humans, free earlobes are dominant over attached earlobes. Cross two heterozygous parents.
Show the parental cross.
Show the Punnett square.
List all of the possible genotypes and their probabilities (as a fraction and as a percent).
List all of the possible phenotypes and their probabilities (as a fraction and as a percent).