Question

nondisjunction genetic disorders

Answer 1

Non-disjunction is the event caused by failure of separation of homologous chromosomes during cell division. This results in daughter cells with abnormal number of chromosomes. The result of this will be imbalance in chromosomal numbers called aneuploidy. Cells with loss of single chromsomes is reffered to as Monosomy and gaining of single extra chromosome is reffered as Trisomy. Example of such conditions are- Turner's syndrome, Down syndrome, Klienfilter syndrome, Edward's syndrome.

Turner's syndrome is loss of a X chromosome. It occurs in females only. It is only survivable monosomy.

Down syndrome is a trisomy of chromosome 21. Child with down syndrome have 3rd copy of chromosome 21. Children with this disorder might have delayed physical growth and a bit less intellectual than the normal kids.

Edward's syndrome is trisomy of chromosome 18. It's a genetic disorder caused by presence of extra copy of whole chromsome 18. Babies born with this synfrome are smaller in size and have heart diseases.

Klienfilter(47, XXY) is most common sex chromosome aneuploidy. It cause infertility in males. Most cases have XXY, but others might have XXXY, XXYY and XXXXY abnomal set of chromosomes.