An Organized Picture of Your Chromosomes!! Karyotypes An Organized Picture of Your Chromosomes!!

Creating a Karyotype During cell division (metaphase), stain the chromosomes and then take a picture. Magnify the picture to make the chromosomes larger. Cut out and place in order pair 1-23 from largest to smallest.

How to determine the sex of the individual. Human Karyotype has 23 pairs of chromosomes. Pair 23 is the sex chromosomes – If the 23rd pair looks identical it is XX, if they look different it is XY. No matter how many chromosomes you see, if there is a shorter chromosome in pr 23 it is male.

Human Karyotype 1 – 22 Autosomal Chromosomes Pair 23 – Sex Chromosomes Male – XY Female - XX Absence of Presence of the Y chromosome determines the sex of the individual

Female Notice the Y spot is there but there is nothing in it.

Male No matter the number of X chromosomes, the presence of a Y makes it a male

What is the point? Use this picture to diagnose chromosomal disorders such as Down Syndrome – Trisomy 21 Turner’s Syndrome – X Klinefelter’s Syndrome – XXY How do chromosomal disorders happen? Nondisjunction – “Not coming apart” When this happens abnormal numbers of chromosomes may find their way into gametes.

Karyotypes Show Chromosomal Mutations Deletion – Loss of all or part of chromosome Duplication – Extra portion of chromosome Inversion – Chromosome is oriented in the reverse direction Translocation – Part of a chromosome attaches to another nonhomologous chromosome

Deletion Karyotype

Duplication Karyotype

Translocation Karyotype

http://www. biology. arizona http://www.biology.arizona.edu/human_bio/activities/karyotyping/Karyotyping.html