Download Problems for Review

Problems for Review
In fruit flies, the gene for straight wings, T, is dominant to the gene for curly wings, t.
__________________
1. If two flies, when bred, produced 98 straight-winged and 102 curly-winged offspring.
What were the most probable parental genotypes?
__________________
2. What were the phenotypes of the parents in question 1?
__________________
3. What was the genotype of the straight-winged offspring in question 1?
__________________
4. What was the genotype of the curly-winged offspring in question 1?
__________________
5. If two different flies, when bred, produced 152 straight-winged and 49 curly-winged offspring.
What were the most probable parental genotypes?
Use the following information to answer questions 6 - 7.
In fruit flies, the gene for brown body color, B, is dominant to the gene for yellow body color, b. The gene for long wings, L,
is dominant to the gene for short wings, l. A brown, short-winged male is bred to a yellow, long-winged female. Of the
offspring produced, half are brown, long-winged and half are yellow, long-winged.
__________________
6. What is the most probable genotype of the male parent?
__________________
7. What is the most probable genotype of the female parent?
In humans, the gene for brown eyes, B, is dominant to the gene for blue eyes, b. A brown-eyed man, whose mother was
blue-eyed and whose father was brown-eyed, and a blue-eyed woman, both of whose parents were brown-eyed, marry.
________
8. What is the woman’s genotype?
________
9. What is the man’s genotype?
________ 10. What is the genotype of the man’s mother?
________ 11. What is the genotype of the woman’s parents?
________ 12. If the man and woman have four children, how many would be expected to be heterozygous for eye color?
________ 13. How many of the four children would be expected to have blue eyes?
________ 14. How many of the four children would be expected to have brown eyes?
In guinea pigs, the gene for black fur, B, is dominant to the gene for white fur, b. The gene for rough coat, R, is dominant
to the gene for smooth coat, r.
________________ 15. If a homozygous black, heterozygous rough pig is bred to a white, smooth pig, what is the
expected genotypic ratio of the offspring?
________________ 16. What is expected phenotypic ratio of the offspring of the cross in question 15?
________________ 17. What is the phenotype of a BbRR parent?
________________ 18. The results of a different cross of guinea pigs are 19 black, rough: 6 black, smooth: 7 white,
rough: 2 white, smooth. What are the most probable genotypes of the parents?
________________ 19. What phenotypic ratio does the 19:6:7:2 most closely resemble?
________________ 20. If a cross between a white rough and a black smooth produced 8 black rough and 9 white
smooth, what is the genotype of the white rough parent?
________________ 21. What is the genotype of the black smooth parent in question 20?
________________ 22. What is the genotype of the black rough offspring in question 20?