Genetics Review

1. Genetics Review

2. In Fruit flies, dumpy wings are shorter and broader than normal wings. The allele for normal wings is dominant to the allele for dumpy wings. Two normal-winged flies were mated and produced 300 normal-winged flies and 100 dumpy-winged flies. What were the parents’ genotypes.

3. Dd X Dd

4. In the following dihybrid cross concerning the traits of tongue rolling and unattached earlobes. TtEe X TtEe What is the probability that an offspring would be a tongue roller with unattached earlobes?

5. 9/16

6. In snapdragons, the allele for tall plants is dominant to the allele for dwarf plants, and the allele for red flowers is incompletely dominant with white flowers (a red flower mated with a white flower has all pink offspring). If a dwarf pink snapdragon is mated with a heterozygous tall white snapdragon, what is the phenotypic ratio of their offspring?

7. ¼ Tall Pink ¼ Tall White ¼ Dwarf Pink ¼ Dwarf White

8. When a black lab is mated with a yellow lab and half of their pups are chocolate and half are yellow labs, what must the genotypes of the parents be? This type of inheritance is called ____________.

9. EeBb X eebb Epistasis

10. Red headed people frequently have freckles. This is best explained by which of the following? a. The genes for these two traits are linked on the same chromosome. b. The genes for these two traits are sex-linked. c. Alleles for these two traits are co-dominant. d. Both parents have red hair and freckles.

11. A

12. Hemophilia is linked to the X chromosome. A Normal man’s father is hemophiliac and his wife has no family history of hemophilia. What is the probability that they will have a child with hemophilia?

13. 0 %

14. For the following pedigree what is the pattern of inheritance? List the genotypes of as many people as possible.

15. Autosomal Recessive

16. If a father is heterozygous A+ and the mother is O-, what are the possible phenotypes and in what percents for their children?

17. 25% A+ 25% A- 25% O+ 25% O-

18. Who can donate blood to a person with A- blood?

19. People with A- or O- blood.

20. Describe how Gregory Mendel studied heredity.

21. By working with pea plants, he was able to see how traits were passed down from one generation to the next. One of his first experiments was to test tall pea plants with short. He expected the offspring to be medium in height but he found out that some were tall and some were short. Through more studies he was able to identify dominant and recessive traits.

22. Challenge problem – worth 2 points A woman’s grandmother had cystic fibrosis and her husband has no known cases of cystic fibrosis in his family but we know there is a 1 in 20 chance that he is a carrier. What is the probability that this couple will have a cystic fibrosis child?