B. Kinetochores begin attaching to spindle fibers. C. Nuclear membrane reforms, chromosomes decondense D. Chromosomes condense, centrosomes migrate to opposite sides of nucleus. E. Sister chromatids separate, move to opposite poles. Drosophila melanogaster has four pairs of chromosomes. Sperm from this species are formed by a meiotic process in which homologous chromosomes pair and segregate but do not undergo crossing over.
Nondisjunction can occur at either the first or second division of meiosis.
It couldn't be the A or B, because the mother can't donate a Y chromosome. A first division non-disjunction would result in an XY gamete, giving an XXY offspring. A. Movement of sister chromatids to opposite poles at anaphase II of meiosis. B. Movement of homologous chromosomes to opposite poles at anaphase I of meiosis. C. Crossing over between homologous chromosomes during prophase I of meiosis.