Mendel’s pea plants exhibited a number of simple dominant/recessive traits. Let’s say a dominant homozygous purple –flowered plant is crossed with a white-flowered plant (recessive). Using P for the purple allele for flower color, and p for the white allele for flower color,
Write the genotypes for each of these two plants.
Purple flowered:
White-flowered:
What gametes might each plant produce?
Purple-flowered:
White-flowered:
If these two plants are crossed, give the genotypes and phenotypes of their offspring. (Use your paper to make a Punnett square, then give the results here.)
Phenotypes:
Genotypes:
Assume that right-handedness (R) is dominant to left-handedness (r) in humans.
What are the possible genotypes of a right-handed person? What is the genotype of a left-hander?
Right-hander:
Left-hander:
Explain how two right-handed people might have a left-handed child.
If a left-handed person who had one left-handed parent has children with a left-handed person, what predictions could you make about the handedness of their children?
In cattle, polled (hornless) (P) is dominant to horned (p). If a breeder of purebred cattle, all of which are polled, suspects that one of her prize bulls is heterozygous and carries the horned allele, how might she determine if her suspicion is correct?
In horses, trotter (T) is dominant over pacer (t). A trotter is mated to a pacer, and the foal they produce is a trotter. Give the genotypes of these three horses.
Trotter:
Pacer:
Foal:
In rabbits, black color is due to a dominant gene, B, and brown color is due to its recessive allele, b. Short hair is due to the dominant gene, S, while long hair is due to its recessive allele, s.
In a cross between a homozygous black, long-haired rabbit and a brown, homozygous short-haired one, describe the nature of the F1 generation. What is the phenotype of the resulting offspring? What is their genotype?
Phenotype:
Genotype:
What does the F2 generation look like?…