A question from my University's Question paper 2016:
A newly identified fruitfly mutant, cyclope eye –large and single in the middle of the head is hypothesised to be autosomal dominant. The experiment started with homozygous wild type females and heterozygous cyclopes males. The data from the F2 generation was 44 wild type males males, 60 wild type females, 110 cyclops males and 150 cyclops females. Does this support or reject the hypothesis$^1$? Use chi square to prove.
I think the following should be a proper approach at solving it:
H0= The proportion of cyclope eyed male and female is not that same,i.e. the gene responsible is not autosomal. $or$ There is an association between the sex of fruitfly and the phenotype.$^2$
H1= The proportion of cyclope eyed male and female is the same, the gene is present on autosome $or$ There is no association between the sex and the phenotype.$^2$
Chi square contingency test with Male and Female (in the columns) and Wildtype and Mutant phenotype (in rows).
Once the H0 is proved wrong (if it is proved wrong), we consider a next Chi-square test, goodness-of fit, where :
H0= The proportion of mutant phenotype is the same as the wildtype i.e. 1:1 ratio is followed
H1=The proportion and the mutant phenotype is greater i.e. the allele responsible is dominant.
When the final H1 is accepted the $^1$hypothesis is correct or else wrong.
$^2$ I'm not sure which one is better / proper.
Is it alright?