KaryotypingBiology

Miss Schwipperty

Questions How many chromosomes come from your

Father? How many chromosomes come from your

Mother? What are chromosome pairs 1-22 called? What is chromosome pair 23 called?

Karyotype

A photograph of an organism’s chromosomes

-homologous chromosomes are grouped together Based on size,

banding pattern, and location of centromere

Karyotype

Helpful in finding chromosomal abnormalities Can NOT tell if

baby has blue eyes!

Are there too many or too few chromosomes?

Are chromosomes missing sections?

Normal Female

Normal Male

Karyotype

Changes in chromosome number occur during NONDISJUNCTION Chromosome

pairs fail to separate during meiosis

Monosomy

Fertilized zygote has only ONE copy of a particular chromosome

Trisomy

Fertilized zygote has THREE copies of a particular chromosome

Monosomy and trisomy are often fatal to the embryo, but not always …

Trisomy 21: Downs Syndrome

Nondisjunction of the sex chromosomes …

Klinefelter’s Syndrome

XXY = male; unusually small testes, sterile. Breast enlargement and other feminine body characteristics. Normal intelligence.

Jacobs Syndrome

XYY = male- Tall with heavy acne- Speech & reading problems- Aggressive tendency???- Fertile

Triple X Syndrome

- XXX = female

- Fertile with normal intelligence

Turner Syndrome

the ONLY viable monosomy Do NOT undergo puberty XO = female ; sterile

Amniocentesis

Usually performed during 2nd trimester (week 14-17)

Small amount amniotic fluid is tested for chromosomal abnormalities

Can you name to following disorders?