Question

The authors genotypes 287 F2 plants. What are the expected numbers of genotype, given the proportions you determined in b? (1 pt)

72 homozygous Dn, 72 homozygous Dg, 143 heterozygous DnDg <- this is the answer I found

Imagine that the observed numbers of F2 individuals of each genotype are: 3 DⁿDⁿ, 144 DⁿD^m, and 140 D^mD^m. Perform a Chi-square analysis to determine whether the authors can reject the null hypothesis of equal segregation of alleles.

Answer 1

Answer:

Based on the given information:

Expected number of different genoypes:

• Expected number of Homozygous DnDn = 72
• Expected number of Homozygous DgDg = 72
• Expected number of Heterozygous DnDg = 143

Observed Number of different genotypes:

• Observed number of Homozygous DnDn = 3
• Observed number of Homozygous DgDg = 140  (** assuming it is DgDg and not DmDm)
• Observed number of Heterozygous DnDg = 144 (** assuming it is DnDg and not DnDm)

Chi Square Test:

Genotype	Observed (O)	Expected (E	(O-E)	(O-E)^2/E
DnDn	3	72	-69	66.1
DgDg	144	72	72	72.0
DnDg	140	143	-3	0.1
Total	287	287	Chi Square Sum	138.2

Degree of freedom = Number of categories - 1 = 3 - 1 = 2

P-value corresponding to Chi square value of 138.2 with 2 degree of freedom is: P-Value is < 0.00001. The result is significant at p < 0.05.

Since P-value is less than the significance level, therefore, the Null Hypothesis is rejected.

Based on the experiemental evidence, the authors can reject the Null hypothesis of equal segregation of alleles.