In pea plants the allele for tall stems (T) is dominant and the allele for short stems (t) is recessive. A plant has the genotype Tt. How tall does it grow?

In peas, round seeds (R) are dominant to wrinkled seeds (r). A seed has the genotype rr. What does the seed look like?

In fruit flies, full-size wings (N) are dominant to short vestigial wings (n). A fly has the genotype NN. Describe its wings.

In guinea pigs, black fur (B) is dominant to white fur (b). A pup has the genotype Bb. What color is its fur?

In cattle, the hornless (polled) allele P is dominant and the horned allele p is recessive. A calf has the genotype Pp. What does its head look like?

In tomato plants, red fruit (R) is dominant to yellow fruit (r). A plant with the genotype Rr grows red tomatoes.

In chickens, a bumpy rose comb (R) is dominant to a single upright comb (r). A hen has the genotype rr. What comb does she have?

In these mice, a black coat (B) is dominant to a white coat (b). A mouse has the genotype bb. What color is its coat, and why?

In peas, a green pod (G) is dominant to a yellow pod (g). A plant is Gg. Which pod color appears, and why?

In dogs, short hair (S) is dominant to long hair (s). A puppy has the genotype ss. What is its coat like?

In cattle, hornless (P) is dominant to horned (p). Two hornless cattle are bred and their calf is horned. What are the two parents' genotypes?

In peas, tall (T) is dominant to short (t). Two tall plants are crossed and some of their offspring are short. What are the parents' genotypes?

In peas, purple flowers (P) are dominant to white (p). A purple-flowered plant is crossed with a white-flowered plant and all 80 offspring have purple flowers. What are the parents' genotypes?

In peas, purple flowers (P) are dominant to white (p). A purple plant crossed with a white plant gives about half purple and half white offspring. What are the parents' genotypes?

In mice, black (B) is dominant to white (b). A litter from two black parents contains both black and white pups. Which cross produced this litter?

In guinea pigs, black fur (B) is dominant to white fur (b). Two white guinea pigs are bred repeatedly and every pup is white. What are the parents' genotypes?

In rabbits, black fur (B) is dominant to brown fur (b). Two black rabbits have a brown kit. What does the brown kit show about its parents?

In peas, green pods (G) are dominant to yellow pods (g). Which cross can produce offspring with all three genotypes, GG, Gg and gg?

In guinea pigs, black fur (B) is dominant to white fur (b). A white female (bb) has many pups with different males. What must be true of every one of her pups?

In dogs, short hair (S) is dominant to long hair (s). One dog in the picture has short hair and the other has long hair. What can you say for certain about their genotypes?

In cattle, a black coat (B) is dominant to a red coat (b). A red calf has the genotype bb. Which term describes this genotype?

In peas, purple flowers (P) are dominant to white (p). Which statement describes a plant's phenotype rather than its genotype?

In guinea pigs, black fur is dominant to white fur. A black guinea pig bred with a white guinea pig produces 12 black pups and 11 white pups. What does this show about the black parent?

A tall pea plant is self-pollinated for several generations and every single offspring is tall. What does this tell you about the original plant's height alleles?

A tall pea plant is self-pollinated and about a quarter of its offspring are short. What does this show about the parent plant?

Gregor Mendel worked out the basic rules of inheritance by crossing pea plants. Why were pea plants a good choice for his experiments?

A pea plant with two tall alleles (TT) always grows tall, no matter how poor its soil is.

Geneticists have bred fruit flies like the one in the picture for more than a hundred years to study inheritance. What makes fruit flies so useful for this work?

In corn, purple kernels are dominant to yellow kernels. A purple-kernel plant is crossed with a yellow-kernel plant and roughly half the kernels on the ear are yellow. What does this show?

In guinea pigs, black fur is dominant to white fur. What can you say about a white guinea pig's fur alleles before doing any breeding at all?

In dogs, short hair is dominant to long hair. A puppy's mother carries two long-hair alleles and its father carries two short-hair alleles. Which statement describes the puppy?

A TT pea plant is pollinated by a tt plant, where T for tall is dominant. What genotype and height do the offspring have?

In cattle, hornless (P) is dominant to horned (p). A PP bull is bred to a pp cow. Describe the calf.

A kitten carries two alleles of the gene for coat length. Where did those two alleles come from?

In fruit flies, full wings (N) are dominant to vestigial wings (n). An NN fly is crossed with an nn fly. What is true of every offspring?

An organism that reproduces sexually inherits one allele of each gene from each parent.

In guinea pigs, black fur (B) is dominant to white (b). A guinea pig with two white alleles can still grow black fur if one of its parents was black.

In peas, purple flowers (P) are dominant to white (p). A plant that inherits one P allele and one p allele has pale lavender flowers.

A Bb guinea pig, where black (B) is dominant to white (b), is having pups. Which allele does it pass to any one pup?

In rabbits, the allele for full-color fur is dominant to the allele for white fur. In a snowy habitat, white rabbits survive better. What does this show?