Dragonfly eye colourChristina Khoo and Selvi Nair

To investigate the mode of inheritance of eye colour in dragon flies.Hypothesis: The purple allele is dominant to the green allele.Let P be the dominant allele for purple eye pigment and p’ be the recessive allele for green eye pigment.

PP X p’p’ Purple green

Pp’ All purpleThe purple allele is dominant. Since the effect of the purple allele masks the effect of the green allele.

Pp’ X Pp’ Purple purple

PP Pp’ Pp’ pp 3 purple : 1 greenThe 3:1 ratio shows that P allele is dominant to p’ allele. This is a typical monohybrid ratio.Chi square test results show that there is no significant difference between the observed and expected ratio and hence follow the 3:1 monohybrid ratio.