Karyotyping Notes

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Karyotyping Notes
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Karyotyping

• karyotype picture of chromosomes
• --chart of chromosome pairs
• --sample of cells taken from an individual or a
  fetus
• --metaphase chromosomes are photographed
• --picture is enlarged and cut apart and arranged
  from longest to shortest in pairs
• --last set represents sex chromosomes (X and Y)

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Steps in Generating a Karyotype

• Perform ultrasound to produce a sonogram (locates
  baby in utero)
• Perform amniocentesis (insert needle into abdomen
  to remove fluid around baby in Moms uterus)
• Examine fluid under scope, isolate cells that are
  intact
• Examine at higher magnification to see DNA
• Take photograph of DNA and enlarge to see details
• Cut out picture of DNA arrange into Karyotype

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Karyotype arranged according to

• A. size of chromosome (largest first)
• B. Arm length
• C. Centromere position
• D. Banding patterns

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Figure 15.14 Down syndrome
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Figure 15.x3 XYY karyotype