- Download the worksheet to save time writing
- Start solving the practice problems
- If you're stuck, watch the video solutions
- See your summary to get more insights

In a study of the inheritance of two genes in pea plants, a researcher crossed a pure-breeding plant with yellow, round seeds (YYRR) to a pure-breeding plant with green, wrinkled seeds (yyrr). All of the F₁ offspring had yellow, round seeds (YyRr). The researcher then crossed the F₁ to each other to produce an F₂ generation.
The results of the F₂ generation are as follows:
Phenotype Number
Yellow, round 602
Yellow, wrinkled 191
Green, round 202
Green, wrinkled 605
Total 1600
Using the chi-square test, which of the following statements can be true?
In guinea pigs, the allele for short hair (S) is dominant over the allele for long hair (s), and the allele for white color (W) is dominant over the allele for black color (w). We then cross a guinea pig that is heterozygous for both traits with a tester and they produce the following offspring:
with parental configuration 1: 45
with parental configuration 2: 51
recombinant 1: 15
recombinant 2: 10
What does this tell us in terms of genetic linkage?
Suppose we study the genetic linkage of two genes in peas. To determine the genetic linkage, we cross a wild-type pea with a mutant pea and obtain offspring with parental configurations and recombinants. We then conducted a test cross in the F1 progeny and obtained another set of offspring (F2). Using the chi-square test, we determined that the genes are not linked. Suppose we used linked genes, what can we expect in the computed P-value after conducting the chi-square test?
Consider that there are five genes p, q, x, y, z. Determine the sequence of genes on the chromosomes if the cross-over percentage between linked genes is as follows:
1) p and y = 25%, 2) p and z = 15%, 3) p and q = 15%, 4) y and x = 10%, 5) z and q = 30%, 6) z and y = 10%.
We observed in the garden that green-seeded (G) peas are dominant over yellow-seeded (g) peas and purple-flowered (P) peas are dominant over white-flowered (p) peas. We conducted an experiment by crossing the dominant true-breeding peas and recessive true-breeding peas and obtained heterozygous offspring. After obtaining the F1 dihybrid, we conducted a test cross by crossing the F1 dihybrid in a recessive true-breeding pea. We then obtain a total of 135 recombinants out of 520 offspring in the F2 progeny. Using these values, what is the distance between gene G and gene P?
The genes for purple eye (p) and vestigial wing (vg) are 10.7 m.u. apart. The following cross was done in Drosophila: p+vg+/pvg x pvg/pvg, and 1000 offspring were obtained. Calculate the total number of recombinant offspring.
The genes for short artisae (s), black body (b) and brown eyes (bw) are present on chromosome 2 of Drosophila. The order of these genes are as follows: s–b–bw. Identify which of the following gametes is not a result of a single crossover in a female with the sbbw+/s+b+bw genotype.