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.
Click on Karyotyping under human
biology and read the Introduction page:
1. What causes a dark band on the chromosome? __ Giemsa dye _
2. What is a centromere? __________ areas where the two chromatids are joined _____
Patient Histories: *Click on Patient Histories. You will be completing a karyotype for Patient A, B & C
*Match the chromosome to its homolog. After all the matches are complete you'll analyze your patient. (Scroll down to view your completed karyotype).
3. What is patient A's history (summarize) _______nearly full term fetus of a 40 year old female______________
4. How many total chromosomes are in your karyotype - count them _47__
The last set of chromosomes is the sex chromosomes, if you have two large chromosomes, your patient is XX (female), one large and one small indicates and XY (male) . What sex chromosomes does your patient have _XX___
Which chromosome set has an extra + __21____
5. What diagnosis would you give this patient (what disease)? ___Down Syndrome______
6. What is Patient B's history (summarize) _______28 year old male, infertile____________________________
7. How many total chromosomes are in your karyotype - count them ___47____
What sex chromosomes does your patient have _XXY____
Which chromosome set has an extra + __X____
8. Finish the notation for this patient's karyotype : 47 X _XY___
9. What is the diagnosis? ______Klinefelter's Syndrome_______________
10. What is patient C's history (summarize)? _____died shortly after birth_________________________
11. How many total chromosomes are in your karyotype - count them ___47_____
What sex chromosomes does your patient have __XY____
Which chromosome set has an extra + _13____
12. Write out the correct notation for this karyotype. ___47 XY +13____
13. What is the diagnosis? ____Trisomy 13 Syndrome_______________
Go to "heredity and traits" --> "How Do Scientists Read Chromosomes"
(Find the answers to the following questions in this area. Browse all sections)
1. What are the three key features used to read chromosomes?
2. Sketch or describe: metacentric, submetacentric, acrocentric
metacentric - centromere is near the center
submetacentric - one arm is much shorter than the other
acrocentric - centromere lies at one end
3. Got to Make a Karyotype - Try it yourself - Create your own karyotype - turning on hints is okay.
Check this box when your karyotype is complete
What did you find difficult about matching the chromosomes? __answers vary, chromsomes can be difficult to match________
4. Go to - Using Karyotypes to Predict Genetic Disorders
What is trisomy? ______extra chromosome, individual has 3 instead of 2 for a group______________
What is monosomy? ____missing chromosome, only one in a pair is present____________________
What is a terminal deletion? ___a chromosome is missing a piece, usually the tip________________
5. For each of the Disorders, describe the chromosome abnormality and the symptoms.
Cri Du Chat - name of this syndrome is French for "cry of the cat," caused by a delection of chromosome #5
Turner Syndrome - missing or incomplete X chromosome, girls with this disorder are shorter than normal, and may fail to start puberty when they should.
Klinefelter Syndrome - males who have Klinefelter syndrome have an extra X chromosome (XXY), males have less muscular body, and grow very little facial or body hair, also infertile
Williams Syndrome - missing genetic material from chromosome 7, causes problems with the circulatory system and heart defects.
Pick from the list of abnormal karyotypes and arrange the chromosomes in a karyotype.
Use the "print screen" button to copy your finished karyotype onto
a word processing document. For "Diagnosis" write the chromosome set
that has the abnormality, and what type of abnormality it is. Print this page
out and turn it in.