Presentation on theme: "Chromosome Disorders. Prenatal Diagnosis Amniocentesis A small sample of the amniotic fluid surrounding the baby is removed using a syringe. The fluid."— Presentation transcript:
The chromosomes from the cells are magnified under a microscope and a picture is taken. The chromosomes are cut out and arranged in homologous pairs in decreasing size order. This is called a karyotype.
As a woman gets older, her chances of having a baby with a chromosome abnormality increases ***remember, a woman is born with all of her egg cells, but meiosis is not yet complete (egg development stops in prophase I until the follicle matures prior to ovulation)
Most cases of Down syndrome are caused by nondisjunction during meiosis Nondisjunction: homologous chromosomes do not separate properly