WT1 gene was discovered in a patient with …………………37. One extra X chromosome in males due to nondisjunction of X chromosome during oogenesis leads to……………. Syndrome. 38. Sex chromosomal abnormalities occur due to …………… changes in chromosomes. 39. In majority of animals, sex is established at the time of ………….. 40. XO Drosophila flies are ……………… but sterile. 41. In bacteria, sex determination is controlled by …………….. 42. The humans, X chromosome does not combine with Y chromosome except for small pieces of ………….. Regions of the telomeres.​