Question

n a certain type of chicken, the allele for gray feathers is recessive to the allele for black feathers, and the allele for a spotted pattern is recessive to the allele for a solid pattern. chickens that are heterozygous for both traits were crossed and the phenotypes for the offspring were recorded (table 1). to determine whether the data are consistent with the expectations for independent assortment, students performed a chi-square analysis. which of the following is the closest to the calculated chi-square value for the experiment? responses

Answer 1

To calculate the chi-square value for the chicken cross data, apply the formula for chi-square analysis by comparing observed outcomes to expected ratios, as predicted by Mendelian genetics laws of independent assortment.

Step-by-step explanation:

Determining Chi-Square Value

To determine whether the data from the cross of chickens with gray and black feathers and spotted and solid patterns are consistent with expectations for independent assortment, a chi-square analysis is used. Independent assortment predicts that each pair of alleles segregates independently of the other pairs of alleles during gamete formation.

In the scenario provided, chickens that are heterozyous for both traits exhibit Mendelian genetics principles.

For a dihybrid cross (AaBb x AaBb), the expected phenotypic ratio is 9:3:3:1 according to Mendel's law of independent assortment.

To determine the chi-square value, you would first need to calculate the expected numbers for each phenotype based on the ratio of 9:3:3:1, then use the formula χ² = ∑ ((observed - expected)² / expected) for each phenotype category.

The sum of these values would provide the chi-square value to compare with a critical value from a chi-square distribution table at a certain degree of freedom to determine if the observed ratios are significantly different from the expected ratios.

Answer 2

To determine whether the data are consistent with the expectations for independent assortment, students performed a chi-square analysis. Without the specific observed and expected phenotypic ratios, the exact chi-square value cannot be determined.

Step-by-step explanation:

In this experiment, the students performed a chi-square analysis to determine whether the data are consistent with the expectations for independent assortment. The chi-square test is used to determine if there is a significant difference between the observed and expected values.

To calculate the chi-square value, the students would first need to determine the expected phenotypic ratios based on independent assortment. If the observed phenotypic ratios match the expected ratios, the chi-square value would be close to 0. If there is a significant difference between the observed and expected ratios, the chi-square value would be larger.

Without knowing the specific observed and expected phenotypic ratios from Table 1, it is not possible to determine the exact chi-square value for the experiment.