KAROTYPING ACTIVITY


In this activity, you will use a computer model to look at chromosomes and prepare a karyotype. You will diagnose patients for abnormalities and learn the correct notation for characterizing karyotypes.

Site 1: The Biology Project at www.biology.arizona.edu
Click on the link that says "Karyotyping" to move to the activity.
Follow the instructions at the site. As you proceed through the lesson, answer the following questions.
Introduction:
1. What causes a dark band on the chromosome?
2. What is a centromere?
Patient Histories:
Complete the karyotype for the patients by matching the chromsome with its homologous pair.
Hint: Use the sizes and banding pattern of the chromosome to help you make the match. (Your choices are highlighted in blue)
You will not be able to proceed until you have correctly matched all the chromosomes.
Patient A
3. (A.1) What notation would you use to characterize Patient A's karyotype?
4. (A.2) What diagnosis would you give for Patient A
Patient B
5. (B.1) What notation would you use to characterize Patient B's karyotype?
6. (B.2) What diagnosis would you give for Patient B
Patient C
5. (C.1) What notation would you use to characterize Patient C's karyotype?
6. (C.2) What diagnosis would you give for Patient C

  1. The dark band is produce by the richness in the base pairs Adenine (A) and Thymine (T).
  2. A centromere is an area where two chromatids are joined.
  3. 47, XX+18.
  4. Down Syndrome with extra chromosome 21.
  5. 47, XXY+17
  6. Klinefelter’s Syndrome with one extra Y chromosome
  7. 47, XY+18
  8. Trisomy 13 Syndrome with one extra chromosome number 13

For "diagnosis" write which chromosome set (#) has the abnormality and whether it is a trisomy (3 chromomes) or a monosomy (1 chromosome) or other type of abnormality, such as a deletion.
J Chromosome Karyotype Diagram. It results in trisomy, because it has 47 chromosomes.