1. A picture of chromosomes arranged by size and shape
Karyotypes
A picture of chromosomes arranged by size and shape

2. To make a Karyotype
Cells are obtained and allowed to grow in a petri dish
As cell grow and divide a chemical is applied to stop Mitosis.
A Pictures is taken (used to be film now digital)
Individual chromosomes are cut and pasted to create diagram

3. Normal Female Karyotype

4. Used as a Diagnositic tool to determine if Chromosomes are Missing or Damaged
Chromosomes are arranged in Homologous pairs
The Largest set comes first
Size decreases as pair number increases
Last pair Consists of Sex chromosomes
Sex chromosomes code for gender and a few other traits
All other pairs are called AUTOSOMES.

5. Normal male Karyotype

6. Normal Human Karyotype
44 Autosomes or 22 pairs
2 Sex Chromosomes or 1 pair
Total 46 Chromosomes or 23 pair
Female XX
Male XY

7. Nondisjunction
When chromosomes fail to separate during Anaphase, the result is known as nondisjunction
Result is having too many or too few chromosomes
Too many chromosomes is called POLYPLOIDY or Trisomy
Too few chromosomes is called MONOSOMY
Disorders resulting from nondisjunction are usually classified by the Number present and the chromosomes number where the problem occurs
Often named for the scientist that discovered the problem
Some always result in death and are not named

8. Turner’s Syndrome Monosomy 45XO One sex chromosome missing
Automatically girl
Always “pre-teen body”
Usually never menstrate

9. Edwards Syndrome Involves 3 copies of 18th chromosome
Mental retardation
Feeding difficulties, cleft palate
Usually die by age 2

10. Down’s Syndrome Trisomy of 21st Characteristic facial and body shape
Can be very low or high functioning but always show mental retardation
Often have heart defects

11. Klienfelter’s Syndrome
Trisomy of Sex Chromosome
47XXY
Tend to be tall and lean, “lanky”
Efeminant—may have breast development or high pitch voice
Mentally retarded
Usually infertile

12. Not all are nondisjunction
Cri du Chat results from a broken or missing arm on the 5th chromosome
Named for the way they cry
1/3 die by age 2

13. Fragile X Missing or broken arm on sex chromosome.
Causes more problems for males who only have one X
Have long face and large ears
Speech problems and low muscle tone