Name __________________________________________________________
HUMAN KARYOTYPING
IDENTIFYING HUMAN CHROMOSOMES
* Visit http://learn.genetics.utah.edu/content/begin/traits/karyotype/. Follow the directions and construct
a human karyotype.
•
As you progress through the chromosomes, what three features change?
•
How many pairs of chromosomes are shown? ________
•
How many individual chromosomes are shown? ________
•
What is the biological sex of this individual?
*Log onto www.explorelearning.com then select their Human Karyotyping Gizmo.
• Look at the SIMULATION pane.
• Use the ARROWS to click through the numbered list of chromosomes
at the bottom right of the pane.
• Click Reset. Then select Subject A from the dropdown menu. At the
bottom of the SIMULATION pane, use the arrows to click through the
numbered list of chromosomes.
*The X and Y chromosomes are called the sex chromosomes
because they determine the sex of the person.
1. Describe how the X and Y chromosomes different from each other in appearance.
• Drag one chromosome from subject A down into the area labeled
Identify.
• Use the left and right arrows to compare the chromosome you picked
with chromosomes 1 through 22 and also with X and Y.
• Drag the chromosome to the appropriate position in the
KARYOTYPING pane on the right.
• Identify all of the remaining chromosomes in sample A and drag them
to the correct position. When you have completed the arrangement of
chromosomes, examine them.
2. Which sex chromosomes are present in the 23rd pair? ______________
3. What is the gender of subject A? (Circle One) Male
Female
• Before you move on the next step, get a "picture" of the karyotype in
the Gizmo.
a. Click COPY SCREEN at the bottom of the Gizmo,
b. open a new word document,
c. add a heading and select Paste.
IDENTIFYING CHROMOSOMAL DISORDERS THROUGH KARYOTYPING
• Select Subject C from the SIMULATION pane.
• Identify each of subject C’s chromosomes.
• Place them on the KARYOTYPING pane.
• Once you have completed the karyotype, take a picture of it.
o Paste the snapshot into the document with your other picture.
o Label it “Subject C.”
4. How does subject C’s karyotype differ from a normal karyotype?
*A chromosomal disorder occurs when a person’s cells do not have
the correct number of chromosomes. The table below lists three
common chromosomal disorders.
Disorder Name
Down syndrome
Description of
Disorder
Extra Chromosome
21
Klinefelter
syndrome
Extra X in male
(XXY)
Turner syndrome
Single X in female
(XO)
Subject
Symptoms
(Circle C,
D, or E)
(list 1-2 from DIAGNOSIS)
C D E
C D E
C D E
• Use the table to determine which disorder subject C has.
• Select the disorder you think Subject C has and circle in the correct row
of the SUBJECT column.
• Click on the DIAGNOSIS tab to check your answer.
• List 1-2 symptoms in the DIAGNOSIS tab in the SYMPTOMS column
of the table.
• Take a picture of the karyotype, paste it in the document, and label it
Subject C.
• REPEAT for Subjects D and E.
* Visit the National Center for Biotechnology Information (NCBI)
Chromosome Map at www.ncbi.nlm.nih.gov/books/NBK22266/.
*Compare the Karyogram of a human male map with Subject A’s karyotype
from the Gizmo.
5. How are these chromosomes different than/similar to those for Subject A in shape, size,
and banding pattern?
*Click on three different chromosomes on the Karyogram of a human male
map.
6. Complete the table on the next page for each chromosome you selected:
*Note: You will need to click on the name of the disease to find
characteristics. A new window containing information about the
disease will open.
Chromosome
#
Approx. #
of Genes
Disease associated with
chromosome
One characteristic of the disease*
7. Based on what you have seen, how does a karyotype allow scientists to diagnose diseases
of a chromosome?
8. Karyotypes can be created for any organism with chromosomes (plants, animals,
bacteria). How might scientists use karyotypes to learn more about living organisms?