Question

2. For each of the following, use the Chi-square technique to determine whether the gene frequencies could be attained due to chance. a. Problems a and b listed in question #1. b. Plants usually don't have blood (although Sanguinaria canadensis, the bloodroot, may be an exception!) but evolution isn't limited only to plants. Consider the following problem: 100 individuals with type o blood, 85 with type A blood, 22 with type B blood, and 15 with type AB blood where the expected probability of each blood type is as follows: Copserved-expected )2 Type O = 45% Type A = 40% Type B = 10% expected Type AB = 5%

Answer 1

Observed values

· Individuals type O= 100

· Individuals with type A = 85

· Individuals with type B = 22

· Individuals with type AB = 15

· Total = 222

Expected values

· Individuals type O= 45% of 222 = 99.9

· Individuals with type A = 40% of 222 = 88.8

· Individuals with type B = 10% of 222 = 22.2

· Individuals with type AB = 5% of 222 =11.1

D.

	O	E	O-E =d	d2	Χ2 =(d2/E)
O	100	99.9	0.1	0.01	0.01/99.9 =0.0001 (approx)
A	85	88.8	-3.8	14.44	14.44/ 88.8 = 0.16 (approx)
B	22	22.2	-2.2	4.84	4.84/22.2 = 0.21 (approx)
AB	15	11.1	3.9	15.21	1.37 (approx.)
Total	222	222			1.7401

D.F = 3

Hypothesis accepted