NAME _______________________________
Human Karyotyping Lab
Background: Occasionally chromosomal material is lost or rearranged during the formation of gametes or during cell division
of the early embryo. Such changes, primarily the result of nondisjunction or translocation, are so severe that the pregnancy
ends in miscarriage – or fertilization does not occur at all. It is estimated that one in 156 live births have some kind of
chromosomal abnormality.
Some of the abnormalities associated with chromosome structure and number can be detected by a test called a
karyotype. A karyotype can show prospective parents whether they have certain abnormalities that could be passed on to their
offspring, or it may be used to learn the cause of a child’s disability. Karyotypes can also reveal the gender of a fetus or test for
certain defects through examination of cells from uterine fluid – a procedure called amniocentesis – or through sampling of
placental membranes. Over 400,000 karyotype analyses are performed each year in the U.S. and Canada.
To create a karyotype, chromosomes from a cell are stained and photographed. The photograph is enlarged and cut
up into individual chromosomes. The homologous pairs are identified and arranged in order by size (with the exception of the
sex chromosomes; these appear last). These tests are typically done on a sample of blood, although any body cell could be
used. The cell must be undergoing mitosis – preferably in metaphase – so that the chromosomes are replicated, condensed,
and visible under a microscope.
(adapted from: http://www.slic.wsu.edu/bios/biol107/107Karyotypesp05.pdf)
Purpose: The purpose of this laboratory experience is:
 Understand what a karyotype is and how it is performed.
 Understand the reason for performing a karyotype, especially for those with a higher risk of genetic defect in their
lineage.
 To determine what genetic defect is present in a chromosome sample.
 To investigate a variety of genetic disorders that commonly occur and are studied in biology classes.
Materials: The following materials are needed to perform this laboratory experience:
-Scissors
-tape
-ruler
-small envelope or baggie
Procedure: The following procedure is utilized to perform this laboratory experience:
1. Using the attached sheets, complete two different karyotypes: One normal male or One normal female and One
from the different disorders of your choice out of the four (Set A-D)
2. Working slowly and carefully, using scissors cut out the longest chromosome on one page and find its’ EXACT
match elsewhere on the page. Cut out this chromosome and tape BOTH chromosomes side by side as “Number
1” on a “data page” that has the heading filled out.
3. Continue this procedure (going from largest to smallest) until you have matched all chromosomes and taped each
of them in the corresponding place on the data page.
4. DO NOT CUT OUT ALL CHROMOSOMES AND THEN ATTEMPT TO MATCH THEM!!! Cut out only one at a
time or you will lose chromosomes.
5. In the event that you have an extra chromosome, DO NOT THROW IT OUT! It is the chromosome that causes
your mutation/disorder and you must match it correctly.
6. Once your chromosomes are all cut out and included in the karyotypes, answer the questions and complete the
lab.
NAME _______________________________
PRE-LAB Questions: Answer the following questions before turning in your lab.
1. Which two karyotypes did you choose to complete?
2. Explain how to determine if your karyotype was male or female?
3. Complete the following table PRIOR to completing the Karyotype
Karyotype #1
Karyotype #2
Individual is a ____________________
Individual is a ____________________
Number of chromosomes: _______
Number of chromosomes: _______
What is the sex? ________________
What is the sex? ________________
Normal or Mutated (circle one)
Normal or Mutated (circle one)
If mutated, name the disorder below:
If mutated, name the disorder below:
4. Define or explain the following terms:
a. haploid
b. diploid
c. homologous chromosomes
d. homologous
e. Monosomy
f. Trisomy
NAME _______________________________
Chromosomes Picture #1
NAME _______________________________
Chromosome Picture #2
NAME _______________________________
Chromosome Picture #3
NAME _______________________________
Chromosome Picture #4
NAME _______________________________
Chromosome Picture #5
NAME _______________________________
Chromosome Picture #6
NAME _______________________________
ANALYSIS QUESTIONS:
1. How does this lab relate to How Cells Divide?
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
2. What characteristics did you use to match up similar chromosomes known as homologous chromosomes?
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
3. Which pairs on the human karyotype are known as autosomes?
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
4. Which pairs on the human karyotype are known as sex chromosomes?
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
5. Down’s Syndrome is known as trisomy 21. What does this mean in terms of the numbers of chromosome and the type
of abnormality?
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
6. Why do you think that monosomy or trisomy of the autosomes are more detrimental to survival than monosomy or
trisomy of the sex chromosomes?
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
NAME _______________________________
Some chromosomal abnormalities that can be detected by karyotyping are listed below:
Abnormality Effects
Extra chromosome 21
Down Syndrome
Associated with mental retardation, characteristic facial features and stature, heart defects, respiratory
infection,leukemia, and Alzheimers disease; occurs in 1 in 700 births in U.S.
XXY
Klinefelter Syndrome
Typically sterile males with abnormally small testes, some female characteristics, normal intelligence;
occurs in 1 in 2000 births
XYY
Double Y Syndrome
Affected individuals tend to be taller as a group, normal intelligence
XXX
Trisomy X
Distinguished from normal XX females only through karyotyping; occurs in 1 in 1000 births. Common
symptoms that can potentially occur include language-based learning disabilities, developmental
dyspraxia, tall stature, low muscle tone (hypotonia), and abnormal bending or curving of the
pinkies toward the ring fingers (clinodactyly).
XO - missing sex chromosome
Turner Syndrome
Sterile (infertile) females with immature sex organs, normal intelligence; occurs in 1 in 5,000 births
Partial chromosome 5
Cru de chat Syndrome
Associated with small head, characteristic cry and facial features, death in infancy or early childhood
Abnormal X chromosome
Fragile X Syndrome
Common genetic cause of mental retardation
NAME _______________________________
Human Karyotype Form
________ _________ _________
1
2
_________ _________
3
4
A
5
B
_________ _________ _________ _________ _________ _________ _________
6
7
8
9
10
11
12
C
_________ _________ _________
13
14
_________ _________ _________
15
16
D
_________ _________
19
20
F
17
18
E
_________ _________
21
22
G
_________ _________
X
Y
NAME _______________________________
Human Karyotype Form
________ _________ _________
1
2
_________ _________
3
4
A
5
B
_________ _________ _________ _________ _________ _________ _________
6
7
8
9
10
11
12
C
_________ _________ _________
13
14
_________ _________ _________
15
16
D
_________ _________
19
20
F
17
18
E
_________ _________
21
22
G
_________ _________
X
Y