1. BEFORE You and your neighbor (at your assigned seat) should have  One blue and one pink construction paper each  One pair of scissors to share  One glue stick to share  One dry erase board set to share In your journal  Why is variety important?  Fill in the Mitosis portion of the table on your worksheet

2. Close your eyes Imagine a mythical creature. A chimera. Picture its body, its head, its wings, the tail. Be creative.

3. Your Chimera What did the creature look like? How many different creatures combined to make it? What would the DNA of such a creature look like? Let’s create the GENOTYPE (genetic composition) for your chimera.

4. Take one of your sheets of paper I don’t care which color you start with. Fold the paper in half (hotdog fold) Cut the paper into a V, with the point of the V attached at the folded edge. What are we making?

5. USING A PEN OR PENC IL Draw lines to divide the (still folded) V into 4 sections.

6. USING A PEN OR PENCIL In the Top section, write in “Head of a _____” as the gene for your Chimera’s head. Also write a Capital A In the next section down, write in “Body of a _____” and a capital B Third section, “Wings of a ___________”, C Fourth Section, “Tail of a ____________”, D What are we writing onto our chromosome?

7. NOW Repeat these steps for your other sheet of paper. Write a NEW SET of characteristics on your second sheet. A new head, new body, new wings, etc. in the same places as the first sheet. Write LOWER CASE a, b, c, and d on each of your new sections.

8. NOT MITOSIS Meiosis

9. Diploid vs Haploid In order to understand Meiosis, you must know there are 2 types of cells; diploid and haploid. A DIPLOID cell has two of each chromosome, one from each parent. This is in contrast to a HAPLOID cell, which only has one copy of every chromosome. Diploid cells comprise the majority of your body, while examples of haploid cells are eggs and sperm.

10. Diploid vs Haploid If a haploid cell has n chromosomes, a diploid cell has 2n  (n represents a number, which is different for every species – in humans, for example, n = 23 and 2n = 46).

11. Homologous Chromosomes Notice that the pairs of chromosomes look very similar. They are not, however, exactly the same. These two chromosomes, one from each parent, are known as homologous chromosomes  (or a homologous pair). They carry the same type of information but they are not identical because each will have slightly different DNA sequences by which you can tell them apart. Examples irl?

12. Mitosis Meiosis Both diploid and haploid cells Makes a PHOTOCOPY of original cell Results: 2 identical cells Only diploid cells Makes 4 HAPLOID cells through 2 divisions Results: 4 GENETICALLY UNIQUE CELLS The difference between Mitosis and Meiosis

13. UNFOLD YOUR V’s into X’s On the blank side of your X, copy the genes from the first side. WHAT PHASE ARE WE IN?

14. The S phase Here, Mitosis and Meiosis are exactly the same. The DNA is replicated in preparation for division.

15. Crossing Over Take ONE GENE from your blue X. Cut it out of the X. Take the SAME GENE from your pink X. Cut it out. Glue these genes back in place ON THE OPPOSITE X. What has this caused?

16. Prophase Prophase I Chromosomes condense Nuclei Dissolves Chromosomes condense Nuclei dissolves Homologous pairs form Crossing over occurs, increasing genetic variation Prophase

17. Time to Move Take your X’s, line them up, side by side in the center of your desk.  What phase is this? Pull the X’s to either side of your desk.  What phase is this? Imagine a nuclei reforming around each X.  What phase is this? Imagine your desk dividing in half. Draw a line with your dry erase marker down the middle of your desk.  What phase is this?  HOW IS THIS ANY DIFFERENT THAN MITOSIS?

18. Metaphase Metaphase I Chromosomes line up along the center. Homologous pairs line up along the center. Mitosis vs Meiosis

19. Anaphase Anaphase I Chromosomes are pulled in half toward either side of the cell. Homologous pairs are pulled apart to either side of the cell. NOTE – it does not matter which side the mother’s or father’s chromosomes end up on This is called INDEPENDENT ASSORTMENT Mitosis vs Meiosis

20. Telophase Telophase I Nuclei reforms around 2 identical DIPLOID nuclei. Nuclei reforms around 2 unique HAPLOID cells (with an extra copy of their unique chromosomes). Mitosis vs Meiosis

21. Cytokinesis Cytokinesis I Cytoplasm divides, 2 identical diploid cells form. Cytoplasm divides, 2 unique haploid cells form. Mitosis vs Meiosis

22. Why the I? Behind each phase of Meiosis? Because this is only the first half. From here, we repeat the phase, PMAT, but now it’s PMAT I and PMAT II. The biggest difference between the two is there is NO DNA REPLICATION between the first and second set. Use your chromosomes and scissors to move through a SECOND ROUND OF PMAT without replication. What happens?

23. Meiosis II Prophase II – Chromosomes condense, nuclei dissolves

24. Meiosis II Metaphase II – Chromosomes line up in the center of the cell

25. Meiosis II Anaphase II – Chromosomes are pulled in half A SECOND TIME

26. Meiosis II Telophase II – Nuclei reform around a HAPLOID nuclei with NO EXTRA COPIES OF THE CHROMOSOME

27. Meiosis II Cytokinesis II – Cytoplasm divides, 4 haploid cells are formed

28. Mitosis Meiosis 2 Diploid SOMATIC CELLS (normal body cells) Identical copies 4 Haploid GAMETES (sex cells – egg and sperm) All unique! Results

29. THE PURPOSE OF MEIOSIS (AND GAMETES) Reproduction

30. Is to create Genetic Variation Take ONE of your Gamete Chimera Chromosomes. Give it to your neighbor. Pair the chromosome you received with one more of your own. We will now create the PHENOTYPE (physical expression of genes) of your chimeran offspring.

31. USING THE PAIRED CHROMOSOMES You must use BOTH CHROMOSOMES to determine your Chimera’s traits. If your trait has a CAPITAL LETTER, it is dominant and MUST BE SHOWN in your Phenotype. IF you have 2 DOMINANT TRAITS, you must show both (i.e. one snake head and one lion head) IF you have 2 RECESSIVE TRAITS THAT DON’T MATCH, you must show a combined trait.