Summer Research Program for Science Teachers
Gateway School for Environmental Research and Technology
What is the purpose of Karyotyping?
IO: 1. Students will be able to define the term karyotype.
2. Students will be able to use karyotypes to make observations and analyze chromosomal errors.
3. Students will be able to explain how karyotyping is used to diagnose specific genetic disorders.
4. Students will make ethical decisions on the use of karyotyping.
Materials: Hardcopy: Karyotyping activity worksheet, and scissors.
On-Line: Courtesy of University of Arizona
Method: This lesson is designed as a hardcopy worksheet activity should computer internet access be unavailable, or as an interactive online activity.
Students will work in groups of 4 using the hardcopy or individually online.
Students will follow the instructions and match-up the chromosomes with their homologous pair. They will have a normal set for comparison.
The finished work will then be analyzed and diagnosed using the chart provided. They will then answer the questions on the worksheet.
POE: Students will read the introduction on karyotyping and how the chromosomes are stained. They will summary the text and define karyotyping.
Amniocentesis Centomere Chromatid
Chromosome Epithelial Cells Homologous Pair
G Band Giemsa Dye Karyotype
Polydactyly Syndrome Trisomy
I. What is a Karyotype?
[How would you arrange the chromosomes? On what features would you focus?]
II. How can we use a Karyotype?
1. Analysis of karyotypes requires a comparison between a normal set of chromosomes and the subjectís chromosomes. If there are missing chromosomes (monosomy), or extra chromosomes (trisomy or polydactyl); or if individual chromosomes have extensions or deletions; the subject will then have a chromosomal disorder.
a. Common Chromosomal disorders:
i. Klinefelter's Syndrome- one or more extra sex chromosomes (i.e., XXY).
ii. Down's Syndrome- Trisomy 21, extra chromosome 21.
iii. Trisomy 13 Syndrome- extra chromosome 13.
III. Karyotyping Activity
Have students write out their group responses to the worksheet questions on the board. Discuss answers as a class.
IV. Ethical Issues
What would you do If you knew in advance that your unborn baby had a chromosomal disorder?
Allow students to brainstorm options and debate proís and conís. Notes will be determined by student responses.
Have students summarize what they learned from the activity and about karyotyping.
Assessment will be based on responses to worksheet question and on summary statements.
VII. New York State Science Standards
S4a, c, d, e; S5b, c, d, e, f; S6a, b, c, d,; S7a, b, d, e.
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