There was a practical in which cross was set up to investigate the inheritance of white eye colour. Wildtype flies (which have red eyes) were crossed with white-eyed flies. A reciprocal cross was carried out with one group doing cross A and other group doing cross B.
Results:
F1 group results
Cross A
Males red eyes 176
Females red eyes 181
Males white eyes 0
Females white eyes 0
F1 class results
Cross B
Males red eyes 0
Females red eyes 147
Males white eyes 140
Females white eyes 0
F2 class results
Cross A
Females red eyes 394
Males red eyes 201
Males white eyes 196
Female white eyes 0 (do not include in calculation as 0)
Cross B
Female red eyes 135
Female white eyes 127
Male red eyes 132
Male white eyes 124
1. Present the results of the D. melanogaster breeding experiment in a suitable format. Include results for cross A and B.
2. Using “+” to indicate the wildtype red-eyed allele and “w” to indicate the mutant white-eyed allele, state the genotypes of the following:
a) Wildtype red-eyed and white-eyed parental flies from cross A and cross B.
b) Males and females from the F1 generation flies from cross A and cross B.
c) Males and females, F2 generation flies from cross A and cross B.
3. Draw Punnett squares to show the ratios expected in the experiment for
a) Parental to F1 generation for cross A and cross B.
b) F1 to F2 generation for cross A and cross B
Total of 4 Punnett squares and they should show both the genotype AND phenotype.
4. Carry out a suitable statistical test on the whole class results of F2 for both cross A cross B. Answer should include
a null hypothesis
degrees of freedom
level of significance
expected numbers of flies
observed numbers of flies
a P value
The critical value (from a statistical table)
Show all of the steps clearly.
Answer if null hypothesis should be accepted or rejected. State conclusion and write how it relates to the genetic basis of white eyes. Brief discussion of results.

There was a practical in which cross was set up to investigate the...