Name_______________________________Date___________________Class Period_________

HEREDITY- 8

Human Chromosome Karyotypes

 

Purpose: Several human disorders are caused by additional, missing, or damaged chromosomes. One way of studying genetic disorders is to observe the chromosomes themselves. In order to do this, cells from a person are grown in a laboratory. After the cells have reproduced a few times, they are treated with a chemical that stops cell division at the metaphase stage. During metaphase, the chromosomes are at the best length for identification.

            The cells are treated further, stained, and then 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 chromosomes are individually cut out. The chromosomes are identified and arranged in homologous pairs. Homologous chromosomes are identical, or matching, chromosomes. The arrangement of homologous pairs is called a karyotype.

 

Procedure:

  1. Go to www.mugansbiologypage.com
  2. Click Q2 Genetics
  3. On the left hand side of the  Q2 Genetics page select this link: Karyotypes read through this link and select the hyperlinks within the page to look at examples of Karyotypes.
  4. Go back to Q2 Genetics page on www.mugansbiologypage.com and select the link labeled “Karyotype Interactive Activities”
  5. Click the example of finished karyotype.
  6. Choose either the unfinished male or the unfinished female and complete using the drag and drop method to arrange the chromosomes into a finished karyotype.
  7. Save finished karyotype by pressing the Print screen button and then paste into paint.  
  8. Complete the following questions for your male/female karyotype.
  9. Arrange unknowns (E, F) into their karyotype.
  10. Identify each unknown by either male or female and its appropriate disorder, if needed.
  11. Save each finished unknown by copying and pasting into paint.
  12. Complete the following questions for each unknown karyotype.
  13. Copy, paste, and label all three karyotypes in a word document to print.
  14. Print all three karyotypes on one Word Document page.

 

*Use Web Resources Such as Google.com, Dictionary.com, and the Karyotypes website to determine your unknown karyotypes and to understand unfamiliar words.

 

Male/Female

Observations

  1. How many autosomes are present in your karyotype?_____________________________
  2. How many sex chromosomes are present in your karyotype? _______________________
  3. Are there any abnormalities? If so, where? _____________________________________

 

 

Unknown #1: Letter _______  Disorder _____________________________  Male / Female

Observations

  1. How many autosomes are present in your karyotype?_______________________
  2. How many sex chromosomes are present in your karyotype? _________________­­­­
  3. Are there any abnormalities? If so, where? _______________________________ ___________________________________________________________________________________________________________________________________________________________________________________________

 

Analysis and Conclusions

1.      Is your karyotype that of a normal person or a person with a genetic disorder?  If it is the latter, identify the disorder?_________________________________________________

2.      Is your karyotype that of a male or a female? Explain. ____________________________

________________________________________________________________________

 

Unknown #2: Letter _______   Disorder ___________________________   Male / Female

Observations

  1. How many autosomes are present in your karyotype?_____________________________
  2. How many sex chromosomes are present in your karyotype? _______________________
  3. Are there any abnormalities? If so, where? _____________________________________

________________________________________________________________________

 

Analysis and Conclusions

  1. Is your karyotype that of a normal person or a person with a genetic disorder?  If it is the latter, identify the disorder?_________________________________________________

2.      Is your karyotype that of a male or a female? Explain. ____________________________ ________________________________________________________________________

 

 

Critical Thinking and Application

  1. What happens during Meiosis that ultimately results in a defect characterized by the addition of chromosomes? By the deletion of chromosomes? ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

 

  1. The human Male determines the sex of his offspring. Explain this statement. ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________