Learning Exercise
Map That Nucleus!
This activity makes use of a website which allows student to manipulate and analyze a human karyotype. A karyotype is a map of the nucleus. More specifically, it is a map, or a layout, of the chromosomes. Humans have 46 chromosomes occurring in 23 pairs, and each parent of a child contributes one chromosome of each pair to that child. 22 of these 23 pairs are known as autosomes, with the final pair being the sex chromosomes. Each pair is numbered, with the largest chromosome pair being pair number one, next largest number two, and so on. Using a REAL karyotype, students are asked to match lone chromosomes with their actual location in that karyotype. After successfully completing that task, the students are then required to analyze the karyotype for any abnormalities that may be apparent.
Course: Biology, Advanced Placement Biology
- Material:
- Karyotypying for Genetic Disorders
- Date last modified:
- November 21, 2005
- Created by:
- Jeff Lukens
- License:
-
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A digitized activity on human karyotyping chromosomes from actual human genetic case studies to determine possible... see more
Exercise
Karyotypes allow doctors to diagnose possible chromosomal abnormalities. The
most obvious of these diagnoses is the presence of an third chromosome where
there is supposed to be only a pair. This is a condition called "trisomy", and
can cause abnormalities such as Down syndrome. A karyotype can be performed and
analyzed prenatally (before birth) or postnatally after birth). A cell's nucleus
whose chromosomes are condensed and which is ready to go through mitosis (cell
division) is used to produce the karyotype. A photograph is taken of the nucleus
and its chromosomes, the chromosomes are cut out of the picture, paired up and
then evaluated. In this activity, you will assume the role of karyotype
analyzer!
Materials/Supplies
Computer with internet access
Procedure
Access the website for this activity, read the background information and
accompanying material, then follow the directions to complete the activity.
After reading the first few paragraphs, click on "Patient Histories" to move to
the activity. Complete the karyotypes of all three patients, making notes and
diagnoses along the way. When you complete the analysis of all three karyotypes,
answer the following questions.
Analysis Questions
1. Describe the chromosomal abnormality of Patient A.
2. What is your diagnosis of this patient?
3. In "Patient A's History", mention is made of epithelial cells. What are
epithelial cells?
4. A procedure called "amniocentesis" is mentioned in "Patient A's History". Do
some research to find out what an amniocentesis is. What did you find?
5. Describe the chromosomal abnormality of Patient B.
6. What is your diagnosis of this patient?
7. Based on Patient B's history, why did he wish to have a karyotype done?
8. From where were the cells obtained from this patient?
9. What SPECIFIC type of cell do you think was used? Why?
10. Describe the chromosomal abnormality of Patient C.
11. What is your diagnosis of this patient?
12. What is different about this abnormality from the abnormalities in Patients
A & B?
13. Patient C is described as having had "polydactyly" and a "cleft lip". Do
some research and describe what each of these is.
14. When a karyotype is performed, what are three characteristics that allow
researchers to correctly pair up the chromosomes?
15. What did you learn about chromosomes from this activity?
most obvious of these diagnoses is the presence of an third chromosome where
there is supposed to be only a pair. This is a condition called "trisomy", and
can cause abnormalities such as Down syndrome. A karyotype can be performed and
analyzed prenatally (before birth) or postnatally after birth). A cell's nucleus
whose chromosomes are condensed and which is ready to go through mitosis (cell
division) is used to produce the karyotype. A photograph is taken of the nucleus
and its chromosomes, the chromosomes are cut out of the picture, paired up and
then evaluated. In this activity, you will assume the role of karyotype
analyzer!
Materials/Supplies
Computer with internet access
Procedure
Access the website for this activity, read the background information and
accompanying material, then follow the directions to complete the activity.
After reading the first few paragraphs, click on "Patient Histories" to move to
the activity. Complete the karyotypes of all three patients, making notes and
diagnoses along the way. When you complete the analysis of all three karyotypes,
answer the following questions.
Analysis Questions
1. Describe the chromosomal abnormality of Patient A.
2. What is your diagnosis of this patient?
3. In "Patient A's History", mention is made of epithelial cells. What are
epithelial cells?
4. A procedure called "amniocentesis" is mentioned in "Patient A's History". Do
some research to find out what an amniocentesis is. What did you find?
5. Describe the chromosomal abnormality of Patient B.
6. What is your diagnosis of this patient?
7. Based on Patient B's history, why did he wish to have a karyotype done?
8. From where were the cells obtained from this patient?
9. What SPECIFIC type of cell do you think was used? Why?
10. Describe the chromosomal abnormality of Patient C.
11. What is your diagnosis of this patient?
12. What is different about this abnormality from the abnormalities in Patients
A & B?
13. Patient C is described as having had "polydactyly" and a "cleft lip". Do
some research and describe what each of these is.
14. When a karyotype is performed, what are three characteristics that allow
researchers to correctly pair up the chromosomes?
15. What did you learn about chromosomes from this activity?
Additional Information: NA