Chi Square and Linkage Practice Problems

A pea plant experiment is conducted to study the genetic linkage of two genes: flower color (W, white or w, purple) and seed shape (R, round or r, wrinkled). Dihybrid plants (WwRr) are crossed with homozygous recessive plants (wwrr) to produce 1,000 offspring. Among the offspring, 470 have the dominant phenotype for both traits, 30 have the recessive phenotype for both traits, 242 have the dominant phenotype for flower color but the recessive phenotype for seed shape, and 258 have the dominant phenotype for seed shape but the recessive phenotype for flower color.
What is the recombination frequency between the genes associated with seed shape and flower color?

Suppose there are three linked genes corresponding to stem length (D), seed shape (C), and flower color (E). Given the following recombination frequencies:

D-C: 12%
D-E: 16%
C-E: 4%

Which of the following is the correct gene sequence?

A pea plant experiment is conducted to study the genetic linkage of two genes: seed color (Y, yellow or y, green) and seed shape (R, round or r, wrinkled). A dihybrid heterozygous (YyRr) plant is crossed with another dihybrid heterozygous (YyRr) plant. They produce the following progeny:

Yellow and round: 120
Yellow and wrinkled: 43
Green and round: 39
Green and wrinkled: 8

What is the chi-square value?

Suppose in a pea garden, the pea that is heterozygous for two traits (tall (Tt) and purple (Pp)) is crossed to a pea that is homozygous recessive (short (tt) and white(pp)) for all the two traits and they produce the following offspring:

Tall and purple: 134
Tall and white: 85
Short and white: 56
Short and purple: 41

What are the genotypes of the recombinants?

Suppose in a pea garden, the crossing of parental peas (TTPP x ttpp) produces F1 progeny that is heterozygous for two traits (TtPp). The F1 dihybrid is then crossed to a pea that is homozygous recessive (ttpp) for the two traits and they produce the following offspring:

Tall and purple: 134
Tall and white: 85
Short and white: 56
Short and purple: 41

What is the recombination frequency between the two genes associated with the pea's height and flower color?

Suppose we cross a flower that is heterozygous for two traits and a tester. It then yields offspring with the following configurations:

Parental combination 1: 72
Parental combination 2: 56
Recombinant 1: 46
Recombinant 2: 30

What is the recombination frequency?

Suppose we cross a wild-type Drosophila with a mutant Drosophila that has vestigial wings and white eyes. We then perform a test cross with the F1 true-breeding individual and obtain the following result in the F2 progeny:

Using the chi-square test, which of the following conclusions is therefore true?

Assuming we have three linked genes for a specific plant. The allele for purple (P) flowers are dominant over the white (p) flowers, the allele for tall (T) plants is dominant over short (t) plants, and the allele for smooth (S) stems is dominant over the hairy (s). A testcross is performed by crossing a plant with PpTtSs genotype with the true-breeding plant with ppttss genotype. They yield the following progeny: 

Which of the following genes are more closely linked to each other?

Assuming we have three linked genes for a specific plant. The allele for purple (P) flowers are dominant over the white (p) flowers, the allele for tall (T) plants is dominant over short (t) plants, and the allele for smooth (S) stems is dominant over the hairy (s). A testcross is performed by crossing a plant with PpTtSs genotype with the true-breeding plant with ppttss genotype. They yield the following progeny: 

Which of the following gives the correct gene sequence?

Assuming we have three linked genes for a specific plant. The allele for purple (P) flowers are dominant over the white (p) flowers, the allele for tall (T) plants is dominant over short (t) plants, and the allele for smooth (S) stems is dominant over the hairy (s). A testcross is performed by crossing a plant with PpTtSs genotype with the true-breeding plant with ppttss genotype. They yield the following progeny:

What are the genotypes of the offspring that have a double crossover allele combination?

Assuming we have three linked genes for a specific plant. The allele for purple (P) flowers are dominant over the white (p) flowers, the allele for tall (T) plants is dominant over short (t) plants, and the allele for smooth (S) stems is dominant over the hairy (s). A testcross is performed by crossing a plant with PpTtSs genotype with the true-breeding plant with ppttss genotype. They yield the following progeny: 

What are the genotypes of the offspring containing the parental alleles?

Which of the following correctly describes linkage disequilibrium?