Complex Inheritance Practice

How are incomplete dominance and codominance similar? Select all that are correct.

How is incomplete dominance different from codominance?

Match the example on the right as either incomplete dominance or codominance or neither.

In a cross between individuals of a species of tropical fish, all of the male offspring have long tail fins, and none of the females possess the trait. Mating two of the F1 fish (the offspring from the first generation) fails to produce females with the trait. However, the trait reappears in 50% of the F2 generation. what is the most likely inheritance pattern of the trait?

Suppose you mate a black rooster with a white hen. The feathers of all the offspring are black. The F2 generation is 3:1, black to white. What is the inheritance pattern in these chickens?

A farmer notices that the length of his watermelons ranges from very long to very short with many watermelons falling in-between at average lengths. What type of inheritance is this?

In a certain species of insect, three eye colors are known: red, orange, and yellow. If purebred red-eyed individuals are crossed with purebred orange-eyed, all the offspring are red-eyed. If purebred orange-eyed are crossed with purebred orange-eyed, all the offspring are orange-eyed. If purebred red-eyed are crossed with purebred yellow-eyed, all the offspring are red-eyed. What is the most likely method of inheritance?

You have a number of plants belonging to an F2 generation. About 1/4 have no thorns, about 1/4 have long thorns, and about 1/2 have short thorns. What type of inheritance is involved?

You discover a species of bird. In the population some have long crests on their heads, some scarcely have any crests, and many have crests showing all possible intermediate lengths. What type of inheritance is involved?

If a type O person marries a type AB person, what blood types could occur in their children? Select all that are possible.

If a type A man marries a type B woman, what blood types could occur in their children? Select all that are possible.

Two parents do not know their blood type. However, the couple has a child with type B blood and a child with type O. What is the only choice listed that could be the parents' blood types?

Jimmy has type A blood. Jimmy is about to undergo a routine operation, but the doctors still want some blood on hand in case a transfusion is necessary. Jimmy’s mother has type A blood. Jimmy’s father has type AB blood. His cousin Alexa has type O and another cousin Nate has type B. Who can donate blood that would be safe for Jimmy?

Match the possible blood types of children (on right) for the following parent combinations (on left). (HINT: always assume A or B type could be carrying the recessive gene for O type!)

Hemophilia (h) is a recessive disease caused by a gene found on the X chromosome. A normal man marries a woman who's father had hemophilia. What is the chance that the couple will have a child with hemophilia?

Colorblindness (c) is a recessive, sex-linked trait. A couple has a family of six: one son is colorblind, and one has normal vision. Two daughters have normal color vision and two are colorblind. One of the parents is colorblind -- which one, and how do you know?

A colorblind woman who carries a hemophilia gene has children with a male hemophiliac with no colorblindness. What is predicted for their sons?

A colorblind woman who carries a hemophilia gene has children with a male hemophiliac with no colorblindness. What is predicted for their daughters?

Before Mendel, the chief theory of heredity was “bloodline inheritance.” According to this theory, the parents’ traits are blended in the offspring, just as two liquids blend when mixed together. Mendel’s theory rested on the idea that traits are transmitted by particles (genes) and do not blend. What genetic evidence supports this older theory?

There is a recessive coat coloration pattern in rabbits, and some dogs and cats called Himalayan. A Himalayan animal has darker fur on colder parts of the body (ears, nose, feet, tail). This is part of a multiple allele system: brown (C) is dominant to both white (c) and to Himalayan (c^h), and Himalayan is dominant to white. A brown male is mated to a Himalayan female, and they have offspring of all three coat colors, brown, white and Himalayan. What are the parents' genotypes?

Look at the following pedigree.

What inheritance pattern is shown here, and how do you know?

Look at the following pedigree.

What inheritance pattern is shown here, and how do you know?

Look at the following pedigree.

What information from the pedigree tells you that this trait must be dominant?

Look at the following pedigree.

Categorize the statements below as "true" or "false".

Labrador Retrievers have three coat colors: Black, Chocolate, and Yellow.

Black (B) is dominant to chocolate (b). There is a second gene, E, which allows the pigment to be put in the fur. If the dog has two recessive alleles (ee) it will be yellow, no matter what the Bb combination is.

You cross a chocolate lab, whose mother was yellow, with a black lab that is heterozygous for both genes. What are the genotypes of the two dogs?

See previous question for information about Lab coat colors.

If you cross the parents from the previous question, what colors of puppies are possible?

A certain yellow lab mated to a certain chocolate lab consistently produces 100% black offspring in multiple litters. How is this possible? Explain using your knowledge of epistasis in Labrador Retrievers and please show your work.