Question

Two autosomal genes control horn color in dragons. Pure-breeding gold-horned dragons were mated to pure-breeding silver-horned dragons. All of the F1 were gold. The F1 were intermated and the F2 generation consisted of 147 gold, 16 silver and 93 bronze.

What is the number for the degrees of freedom?

What is the critical value? Round to two decimal places.

What is your conclusion from the chi-square test?

Select one:

Fail to reject Ho

Reject Ho

Answer 1

Given,  Gold = 147 ; Silver= 16 ; Bronze= 93. Total = 256

number for the degrees of freedom= total number of classes (n) - 1

= 3-1 = 2

The probability of 0.05 is the critical value.

Observed Value	Expected Value
147 gold	(9/16)x 256=144
16 silver	(1/16)x 256= 16
93 bronze	(6/16)x 256= 96
Total = 256	Total= 256

Chi square = (observed value- Expected value)/ Expected value

=0.1250

probability of chi-square value is greater than 0.90

the probability has greater value than 0.05

Hence, the data fits 9:6:1 ratio