Supplementary Genetics Worksheet



Supplementary Genetics Worksheet

1. What would the offspring be the genotype ratio and phenotype ratio in a cross between a tan flower and a homozygous white flower if white is dominant?

2. What is the F2 genotype and phenotype ratio of a cross between homozygous round and wrinkled peas if wrinkled is recessive?

3. What will be the F1 from a heterozygous tall plant and a homozygous short plant if tall is dominant?

4. If snapdragons have incomplete dominance in flower color, what would be the result between an orange (homozygous) and white (homozygous) parent?

5. If black color is dominant in Labrador retrievers over “off-yellow”, how could an animal breeder determine if the male dog was homozygous or heterozygous?

6. If fruit shape of round is dominant in tomatoes over pepper-shaped, what is the phenotype and genotype ratio of the F2 from a cross between a homozygous round parent and a homozygous pepper-shaped plant?

7. What type of dominance would be shown in roses if a cross between two bushes produced: 25 red, 31 yellow and 61 coral roses?

8. Describe the parents of a family of seven black and two white guinea pigs if black is dominant.

9. Albinism is inherited as a recessive lethal (causes death) trait in many species of corn. If a green plant has produced both green and albino offspring. What percentage of the green offspring would you expect to carry the recessive allele for albinism?

10. In cattle the polled (P) or hornless condition is dominant to the having horns (p). A certain bull was mated to 3 cows; the first cow was horned and had a polled calf; the second cow was horned and had a horned calf; the third cow was polled and had a horned calf. Produce a pedigree chart showing the genotypes of each animal.

11. A tomato plant of unknown genotype, but bearing spherical fruits was crossed with one of pear-shaped fruits. This cross-resulted in 131 plants with spherical fruits and 134 plants with pear-shaped fruits. What were the genotypes of the parents?

12. A tomato plant that had spherical fruits was crossed with another that also had spherical fruits. The F1 generation resulting from this cross consisted of 127 plants with spherical fruits and 41 plants with pear-shaped fruits. What were the genotypes of the parents?

13. When a homozygous red-flowered snapdragon plant is crossed with a homozygous white flowered plant, all of the resulting F1 generation have pink flowers. If one of these F1 plants is self-pollinated, what fraction of the resulting F2 plants will have red flowers and what fraction will have white?

14. In chickens, a certain gene (C) is lethal in the homozygous state. Affected individuals die before they hatch from the egg. Heterozygous chickens (Cc) are known as creepers because of their short, squatted appearance. Individuals homozygous for the allele are normal.

a. If a creeper rooster were mated to normal hens, what types of frequencies of offspring would you expect?

b. In a cross between creeper roosters and creeper hens, what proportions of the eggs fail to hatch?

c. Does this example characterize the phenomenon of dominance or incomplete dominance? If a lethal mutant gene were truly dominant, what would happen to it?

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download