INHERITANCE AND PREDICTING
GENETIC TRAITS
Monohybrid crosses
Two parents that differ in one characteristic breed
A male fly with purple eyes and a wild type of female fly
,Punnet square
, Null Hypothesis: the ratio of red eyes and purple eyes will be 3:1 because of Mendel's law of
segregation. It explains the segregation of alleles during meiosis.
Heterozygous and homozygous dominant individuals being phenotypically identical, the law
supports Mendel’s observed ratio.
Chi-test
Observed Expected O-E (O-E)2 (O-E)2/E
Red (3) 736 765.75 -29.75 885.0625 1.55811296
Purple (1) 239 243.75 -4.75 22.5625 0,092564102
56
Total 975 1.248375399
Critical value= 3.841 Conclusion= critical value is smaller than 3.842 so there is no statistically
significant difference between observed and expected values. It follows the 3:1 ratio.
Male fly with white eyes with a wild-type female fly
GENETIC TRAITS
Monohybrid crosses
Two parents that differ in one characteristic breed
A male fly with purple eyes and a wild type of female fly
,Punnet square
, Null Hypothesis: the ratio of red eyes and purple eyes will be 3:1 because of Mendel's law of
segregation. It explains the segregation of alleles during meiosis.
Heterozygous and homozygous dominant individuals being phenotypically identical, the law
supports Mendel’s observed ratio.
Chi-test
Observed Expected O-E (O-E)2 (O-E)2/E
Red (3) 736 765.75 -29.75 885.0625 1.55811296
Purple (1) 239 243.75 -4.75 22.5625 0,092564102
56
Total 975 1.248375399
Critical value= 3.841 Conclusion= critical value is smaller than 3.842 so there is no statistically
significant difference between observed and expected values. It follows the 3:1 ratio.
Male fly with white eyes with a wild-type female fly
