Interpreting Karyotypes

Interpreting Karyotypes

Purpose: To evaluate the impact of biotechnology on the individual, society and the environment, including medical and ethical issues and analyze how heredity and family history can impact personal health.

Background information:

Several human genetic disorders are caused by extra, missing, or damaged chromosomes. In order to study these disorders, cells from a person are grown with a chemical that stops cell division at the metaphase stage. During metaphase, a chromosome exists as two chromatids attached at the centromere. The cells are stained to reveal banding patterns and placed on glass slides. The chromosomes are observed under the microscope, where they are counted, checked for abnormalities, and photographed. The photograph is then enlarged, and the images of the chromosomes are individually cut out. The chromosomes are identified and arranged in homologous pairs. The arrangement of homologous pairs is called a karyotype. In this investigation, you will use a sketch of chromosomes to make a karyotype. You will also examine the karyotype to determine the presence of any chromosomal abnormalities.

Procedures:

Part A. Analyzing a Karyotype

1. Observe the normal human karyotype in Figure 1. Notice that the two sex chromosomes, pair number 23, do not look alike. They are different because this karyotype is of a male, and a male has an X and a Y chromosome.

[pic 1]

1. Observe Human karyotypes 2-6.
2. Identify the chromosomal disorder
3. Determine the gender of the individual.
4. Complete the data table
5. Answer conclusion questions

Observations/Data Analysis:

Chromosomal abnormalities present in each karyotype. Record the genetic defect, associated with each type of chromosomal abnormality present.

Figure 2

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Figure 3

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Figure 4

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Figure 5

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Figure 6

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Figure 7

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Conclusion:

        1. What is meiosis? How many cells are produced in meiosis? Are they identical or