1. Chapter 27 Human Genetics

2. Chapter 27.1 Notes 3 things about chromosomes 1.Humans have 46 chromosomes in all body cells. 2.Humans have 23 chromosomes in all sex cells (sperm or egg). 3.Different organisms have different #’s of chromosomes.

3. Amniocentesis is a way of looking at the chromosomes of a fetus. 23 rd pair of chromosomes determine sex (male/female) they are called sex chromosomes. Female= XX and Male= XY Autosomes are chromosomes that do NOT determine sex (1-22 nd pairs)

4. Amniocentesis Human Karyotype Autosomes pairs 1-22 Sex cells the last pair (23)

5. Work Cited “amniocentesis”. April 30, 2007. http://health.yahoo.com/media/mayoclinic/i mages/image_popup/pr7_amnio.jpg http://health.yahoo.com/media/mayoclinic/i mages/image_popup/pr7_amnio.jpg “Karyotype”. April 30, 2007. http://www.laskerfoundation.org/rprimers/g nn/wagn/images/karyotype.gif http://www.laskerfoundation.org/rprimers/g nn/wagn/images/karyotype.gif “Purple Karyotype”. April 30, 2007. http://fairmanstudios.com/images/human_ genetics.jpg http://fairmanstudios.com/images/human_ genetics.jpg