Chromosomes & Karyotyping

As you get started: Use the notecard provided for this “Karyotyping Activity” As you look through the first few slides, answer the following questions on your notecard: (Note: you’ll turn this in today!) What’s the basic job description of a genetic counselor? What are karyotypes? What types of information can a karyotype provide?

What is genetic counseling? Visit the website: 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.

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: Order an amniocentesis to get some cells from the fluid around the fetus. Look at the chromosomes (smear) under a microscope and take a picture of them. Arrange the chromosomes based on size, centromere position, and banding patterns.

Step 1 of the Process Remove a small sample of fluid. Ultrasound ensures baby isn’t hurt! Examine DNA for various disorders Amniocentesis

Chromosome Smear

Chromosomes Ordered

8 7 6 5 4 3 1 2 16 15 14 13 10 11 12 9 XX Female 22 21 19 20 18 23 17

Arranging the chromosomes in this manner is called a karyotype.

Karyotype

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.

Genetic Disorders and Chromosomes Causes can be: Additional chromosomes Missing chromosomes Translocation

For simplicity we will use the following “cartoon” chromosomes to show different karyotypes that result in genetic disorders.

Your TASK 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. Check with your teacher to see that you’ve correctly identified the disorder. Start constructing a PPT presentation.

8 7 6 5 4 3 1 2 16 15 14 13 10 11 12 9 XY Male 22 21 19 20 18 23 17

8 7 6 5 4 3 Disorder #1 1 2 16 15 14 13 10 11 12 9 22 21 19 20 18 23 17

8 7 6 5 4 3 Disorder #2 1 2 16 15 14 13 10 11 12 9 22 21 19 20 18 23 17

8 7 6 5 4 3 Disorder #3 1 2 16 15 14 13 10 11 12 9 22 21 19 20 18 23 17

8 7 6 5 4 3 Disorder #4 1 2 16 15 14 13 10 11 12 9 22 21 19 20 18 23 17

8 7 6 5 4 3 Disorder #5 1 2 16 15 14 13 10 11 12 9 22 21 19 20 18 23 17

8 7 6 5 4 3 Disorder #6 1 2 16 15 14 13 10 11 12 9 22 21 19 20 18 23 17

8 7 6 5 4 3 Disorder #7 1 2 16 15 14 13 10 11 12 9 22 21 19 20 18 23 17

8 7 6 5 4 3 Disorder #8 1 2 16 15 14 13 10 11 12 9 22 21 19 20 18 23 17

8 7 6 5 4 3 Disorder #9 1 2 16 15 14 13 10 11 12 9 22 21 19 20 18 23 17