The degree of freedom table is available online Please answe

The degree of freedom table is available online. Please answer A&B for question 2

In humans, the dominant allele N causes an abnormal shape of the patella in the knee (n is the normal allele). A separate gene affects finger length, and the dominant allele B causes abnormally short fingers, whereas b gives normal length. A study focused on people who have both abnormal patellae and short fingers (they most likely have the genotype N/n B/b). They inherited the N allele from one parent and the B allele from the other parent. These N/n B/b individuals mated with normal spouses. (The spouses had no history of abnormal patellae or short fingers in their families; they can be assumed to be homozygous normal.) 40 progeny were boom; they are classified as follows. Using the chi square test, determine whether there is significant linkage between the B/b and the N/n gene. X^2 = P = linked? If you conclude there is linkage, what is the distance between the two genes?

Solution

Answer:

a). N/n; B/b x n/n; b/b

N/n B/b : N/n b/b ; n/n B/b ; n/n b/b

1:1:1:1

Chi-square vale = 22.60

The degrees of freedom = 4-1 = 3

p value = 0.00004893

The genes are not linked

Phenotype	Observed(O)	Expected (E)	O-E	(O-E)2	(O-E)2/E
Normal	3	10	-7	49.00	4.90
Abnormal knees and fingers	2	10	-8	64.00	6.40
Abnormal knees only	17	10	7	49.00	4.90
Abnormal fingers only	18	10	8	64.00	6.40
	40				22.60