Chi-squared and codominance

what is chi-squared used to test ?

if observed frequency fits the frequency you expected/ predicted

what do you need in chi-squared ?

• large smaple size

• descrete categories

• only use raw data

formula for chi-squared ?

X² = (O-E)² / E

then add both sets of data if they're are 2

method to work out chi-squared ?

1. work out expected results (E)

2. collect real data (O)

3. work out the difference (O-E)

4. square results (O-E)²

5. divide by expected values (O-E)² / E

6. add all values

7. compare results with chi-squared table

how to write the evaluation for chi-squared ?

If the value is higher than 5% value (3.84), then the differences are sigificant & not due to chance meaning we accept the null hypotheisis

how do you know if we accept or reject the null hypothesis?

• if the X² value if larger than the 5% value then we reject the null hypothesis

• if the X² value is smaller than the 5% value then we accept the null hypothesis

what is codominance ?

alleles are codominanat iff they're both expressed in the phenotype of hetrozygous

how do you write codominance ?

by two capital letters superscript to the letter representing the gene

e.g. C^r C^w

example of codominance ?

C^r C^r = hmozygous red flower

C^r C^w = hetrozygous pink flower

C^w C^w = homozygous white flower