Corn and Mendelian Genetics

Question

Red Smooth. Red Wrinkled. Yellow smooth yellowwrinkled

#Expected. 25. 25. 25. 25

#observed. 29.6. 53.4. 7.2. 9.8

X² value. 0.85. 32.26. 12.67. 9.24

The data above is from genetic tracking two traits inherited in Corn.

Use the X² values provided to find the sum of the X² for this stimulation. Round your answer to the nearest tenth.

Answer 1

This question is just asking you to add the X² ("chi square") values, which were provided in the table.

So ∑X² = 0.85+32.26+12.67+9.24 = 55.02

(round to the nearest tenth = 55.0)

What's more important is that you understand the importance of finding the sum of the X² values - what's the point? Why do this in the first place?

It's for a pretty nifty statistical test called the "chi-square test". "Chi square" is represented by "X²". We use this to test hypothesis involving something called a p-value. So for example, our hypothesis here could be all four possible expected phenotypes will be in a 1:1:1:1 ratio. Using this chi-square value, along with a p-value, we can see if we can accept or reject our hypothesis. The smaller the p-value, the more likely we are to reject our hypothesis.