Did Mendel fake is data?. Do a quick internet search and can you find opinions that support or reject this point of view. Does it matter? Should it matter?. Does the data fit?.
78 to 22 fit?? 85 to 15?
A way to state expected outcome
Example 1: Hybrid parents will produce a 3:1 genotypic ration (predicted values based on punnett square analysis)
Example 2: Flipping a coin should land on heads 50% of the time.
**Chi-square is used to REJECT a hypothesis not to PROVE it.
If this coin is fair…then we would expect the chi-square analysis to show us the results are due only to chance and not due to some other hypothesis.
Let’s look how coin data either:
Rejects a hypothesis that a coin is fair or
Suggests that the hypothesis that a coin is fair is likely.
2 = (55 - 50)2 / 50 + (45 - 502 / 50
= (5)2 /50 + (-5)2 / 100
= 25 / 50 + 25 / 50
= 0.50 + 0.50
Question: Is this corn the result of the following dihybrid cross:
PpSs X PpSs
-First do the Punnett Square
-Find the expected outcomes
-Compare actual to expected by doing chi square. Share your results with a nearby group.
Introduction: How does the dihybrid cross show Mendel’s Law of Independent Assortment? Identify the traits you will be looking at in the corn.
Hypothesis: What do you expect from crossing two heterozygotes—may show a Punnett Square.
Methods: How did you count a random sample of the corn? What does each kernel on the corn represent?
Data and analysis:
-Chi-square analysis for your data.
-Chi-square analysis for another group’s data.
-Trend related to each chi-square analysis.
-Explain how the chi-square analysis can confirm Mendel’s Law of Independent Assortment.
-Discuss what genetic linkage is and why this would cause you to reject the null hypothesis shown in a dihybrid cross.
How can Chi-square be used to analyze these results?
Go back to the genetic recombination problem…do a chi-square analysis as if it was not linkage. What does your analysis tell you?