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Published byWinifred O’Neal’ Modified over 8 years ago
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Chromosomes & Karyotyping
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As you get started: Prepare a spot in your notebook for this “Karyotyping Activity” – As you look through the first few slides, answer the following questions: 1.What’s the basic job description of a genetic counselor? 2.What’s a karyotype and what can it tell us?
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What is genetic counseling? Visit the website: http://www.sciencebuddies.org/science-fair- projects/science-engineering- careers/Genom_geneticcounselor_c001.shtml# whatdotheydo http://www.sciencebuddies.org/science-fair- projects/science-engineering- careers/Genom_geneticcounselor_c001.shtml# whatdotheydo Read the information about genetic counseling and then return to this activity.
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How are chromosomes used to help genetic counselors? Genetic counselors can determine if an unborn child will have any potential problems based on the number of chromosomes in their cells. In order to look at the chromosomes they will: 1)Order an amniocentesis to get some cells from the fluid around the fetus. 2)Look at the chromosomes (smear) under a microscope and take a picture of them. 3)Arrange the chromosomes based on size, centromere position, and banding patterns.
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Step 1 of the Process Remove a small sample of fluid. Ultrasound ensures baby isn’t hurt! Examine DNA for various disorders Amniocentesis
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Chromosome Smear
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Chromosomes Ordered
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1 3 2 5 4 7 6 10 9 11 8 14 17 13 12 16 15 18 21 19 23 22 XY Male 20
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Arranging the chromosomes in this manner is called a karyotype.
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Step 2 (and beyond): Karyotype
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Humans have 46 chromosomes in each of their cells (other than egg/sperm which have 23). Male and Female chromosomes look mostly identical except for the # of sex chromosomes (X and Y). There are 22 pairs of chromosomes (1-22) that everyone gets … these are called autosomes.
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Genetic Disorders and Chromosomes Causes can be: Additional chromosomes Missing chromosomes Translocation
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For simplicity we will use the following “cartoon” chromosomes to show different karyotypes that result in genetic disorders.
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Your TASK 1)Arrange the chromosomes for the Disorder # your teacher has assigned you (ASK ME FOR A #!) and determine if something has gone wrong by comparing it to the normal karyotype handouts. Start by moving the #1 chromosomes (largest) into the correct position and so on. 2)Check with your teacher to see that you’ve correctly identified the disorder. 3)Start constructing a PPT presentation.
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1 3 2 5 4 7 6 10 9 11 8 14 17 13 12 16 15 18 21 19 23 22 XX Female 20
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Disorder #1 1 3 2 5 4 7 6 10 9 11 8 14 17 13 12 16 15 18 21 19 23 22 20
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Disorder #2 1 3 2 5 4 7 6 10 9 11 8 14 17 13 12 16 15 18 21 19 23 22 20
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Disorder #3 1 3 2 5 4 7 6 10 9 11 8 14 17 13 12 16 15 18 21 19 23 22 20
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Disorder #4 1 3 2 5 4 7 6 10 9 11 8 14 17 13 12 16 15 18 21 19 23 22 20
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Disorder #5 1 3 2 5 4 7 6 10 9 11 8 14 17 13 12 16 15 18 21 19 23 22 20
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Disorder #6 1 3 2 5 4 7 6 10 9 11 8 14 17 13 12 16 15 18 21 19 23 22 20
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Disorder #7 1 3 2 5 4 7 6 10 9 11 8 14 17 13 12 16 15 18 21 19 23 22 20
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Disorder #8 1 3 2 5 4 7 6 10 9 11 8 14 17 13 12 16 15 18 21 19 23 22 20
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Disorder #9 1 3 2 5 4 7 6 10 9 11 8 14 17 13 12 16 15 18 21 19 23 22 20
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