1. Do Now Why are chromosomes important? How many chromosomes do humans have? What is a genetic disorder?

2. Objectives To understand what “karyotyping” is and how it is used to determine genetic disorders. To explain what a monosomy is vs. a trisomy. To complete a karyotyping exercise to determine what type of genetic disorder a hypothetical baby would have.

3. Chromosomes Most humans have 46 chromosomes Any human that has more or less is due to something called “non-disjunction” which happens during Meiosis.

4. Meiosis In meiosis, normal human cells that contain 46 chromosomes create new cells that contain half of that-23. (SO WE AREN’T MUTANTS WITH 92 CHROMOSOMES!!)

5. Non-disjunction During meiosis, something can go wrong during anaphase (when the chromosomes are pulled apart) causing a cell to have too many, or not enough chromosomes. Lets watch as two biology students demonstrate this process with twizzlers and m&ms… - NondisjunctionNondisjunction

6. Karyotypes Diagram of our pairs of chromosomes used to determine disorders. Contain 22 pairs of autosomes and 1 pair of sex chromosomes. Female= X X Male = X Y

7. Karyotype Lab 1)Read about each of the disorders that can be found in the packet. Fill in the chart with the necessary information. 2)Obtain a baby from Ms. B. With your partner 3)Construct a “karyotype” that shows your baby’s chromosomes in order from 1-23. Name the baby and write it’s sex and it’s disorder on a piece of construction paper if it does not have a disorder, write “normal”. 4)Refer to the karyotype on the board as an example.