Question

MBG 1000 Assignment #5: Gametogenesis, Melosis & sex chromosomes (PART B) Question 3: A baby boy is bom with Klinefelter Syndrome. It is suggested that this syndrome occurred as a consequence of chromosomal nondisjunction during meiosis I of spermatogenesis. Use a diagram to indicate the sex chromosome composition of both secondary spermatocyte nuclei of the boy's father. Draw the sex chromosome composition of the nuclei of the final four sperm cells produced by spermatogenesis, the sex chromosome composition of the nucleus of a normal mature egg cell, and finally the sex chromosome composition of the nuclei of potential zygotes that can form should each sperm cell fertilize the egg cell. Identify the zygote(s) that represents Klinefelter Syndrome. Indicate the sex chromosome number in each of the zygotes produced.

Answer 1

Question 3

Answer- Klinefelter syndrome occurs due to chromosomal trisomy with the affected individuals have sex chromosome composition of XXY. The following is the sex chromosome composition of nucleic at different stages -
Sex chromosome composition of boy's tathen x x х ч Meiosis I (Non-disjunction) Puma/ spermatodyte 88 secondary Meiosis 7 spermatocytes Meiosis a DO х ч Monosomy Trisomy Monosomy Prisomy sperm cells produced by spermatogenesis sex chromosome composition of the nucleus of a normal mature egg cell

sex chromosome composition of the nuclei. of potential 34 gotes that can form from each sperm cell fertilize the egg cell. x x 9 monosomy monosomy (xo) (xo) Torisomy (xxy) Trisomy (xx4) Klinefelter Syndrome