Comparing and Contrasting Mitosis & Meiosis

Objectives Understand the differences between mitosis and meiosis Recognize the relationships between mitosis and genetic continuity, and between meiosis and genetic variation, among living things Use models to understand such concepts as nondisjunction, crossing over and trisomy.

Instructions Copy this power point presentation as a template to your own student folder. Name it Last name, first name Copy and paste the pre-drawn pictures in slide 4 and 5 to the correct slides on the template. Follow the instructional notes at the bottom of each page. Feel free to improve the sketches or add other pieces such as spindle fibers if time permits.

Left and right sister chromatids of the paternal #1 chromosome. Left and right sister chromatids of the maternal # 1chromosome. Left and right sister chromatids of paternal # 2 chromosome. Left and right sister chromatids of maternal # 2 chromosome. B A A B b a a b d c c d Click on the chromosomes to select them, then copy. Paste them into the slide you want. D C D C

Left and right chromatids of # 1 chromosome. After crossing over Left and right chromatids of other #1chromosome. Left and right chromatids of # 2 chromosome. Left and right chromatids of other # 2 chromosome. B A A b B a b a D c c d Only use these chromosomes for the phases of Meiosis after prophase I. These chromosomes have exchanged pieces of DNA with their partner homologue. D C d C

Interphase before replication Mitosis Haploid or diploid 1n or 2n Place one half of each sister chromatid from slide # 4 in the cell to represent the cell before the DNA has replicated. They should be randomly distributed. In reality the chromosomes would not have coiled up yet. The DNA would be in the form of chromatin . Draw a nuclear membrane around the chromosomes. In the text box delete the word haploid or diploid if it is not appropriate. Do the same with 1n or 2 n. Continue doing that on each slide. Answer the questions which correspond to this phase.

Interphase after replication Mitosis Haploid or diploid 1n or 2n Copy all the chromosomes from the previous slide and paste on to this one so their relative positions in the cell do not change. Copy the other half of each chromosome from slide 4 and connect it to its sister chromatid as a double chromosome. This represents the cell after the DNA has replicated. In reality the chromosomes would not have coiled up yet. The DNA would be in the form of chromatin. Draw a nuclear membrane around the chromosomes. Answer the questions which correspond to this phase.

Prophase Mitosis Haploid or diploid 1n or 2n Select all the chromosomes from the previous cell by dragging a box over them with your mouse. Copy them and place them in this slide. Move them a bit so they are still randomly distributed. The nuclear membrane would be disintegrating but still present. You can show this by selecting the membrane and masking it a dashed line. Answer the questions which correspond to this phase.

Metaphase Mitosis Haploid or diploid 1n or 2n Copy the chromosomes from the previous cell and place them in this slide. The nuclear membrane’s complete disintegration marks the beginning of this phase. The chromosomes migrate to the equator. Place them along an equator which runs from the top to the bottom of the cell. This marks the end of metaphase. Answer the questions which correspond to this phase.

Anaphase Mitosis Haploid or diploid 1n or 2n Copy the chromosomes from the previous cell and place them in this slide in the same relative positions. The sister chromatids separate and migrate towards opposite sides of the cell. Place them as they move apart. Be sure you are deleting either haploid or diploid in each slide.

Telophase & Cytokinesis Haploid or diploid 1n or 2n Copy the chromosomes from the previous cell and place them in this slide in the same relative positions. The sister chromatids have moved to opposite sides of the cell. They start to uncoil and the chromosomes disappear. Two new nuclear membranes form around them. Place them in the newly forming cells and draw the nuclear membranes. Answer the question.

Interphase after Mitosis Haploid or diploid 1n or 2n Copy the chromosomes from the previous cell and place them in this slide. Draw the nuclear membranes. Answer the questions which correspond to this phase.

Interphase before replication Meiosis Haploid or diploid 1n or 2n Place one half of each chromosome in the cell to represent the cell before the DNA has replicated. In reality the chromosomes would not have coiled up yet. Draw a nuclear membrane around the chromosomes. The DNA would be in the form of chromatin. In the text box delete the word haploid or diploid if it is not appropriate. Do the same with 1n or 2 n. Continue doing that on each slide. Answer the questions which correspond to this phase.

Interphase after replication Meiosis Haploid or diploid 1n or 2n Place the both halves of each chromosome in the cell connected as double chromosomes to represent the cell after the DNA has replicated. They should be randomly distributed. In reality the chromosomes would not have coiled up yet. The DNA would be in the form of chromatin. Draw a nuclear membrane around the chromosomes.

Prophase I Meiosis Haploid or diploid 1n or 2n Copy the chromosomes from the previous cell and place them in this slide. The nuclear membrane would be disintegrating but still present. In Prophase I the homologous chromosomes lie side by side and exchange pieces in a process called crossing over. Show this by placing them extra close together so they slightly overlap with the partner homologue. Answer the questions which correspond to this phase.

Metaphase I Meiosis Haploid or diploid 1n or 2n The nuclear membrane’s complete disintegration marks the beginning of this phase. From now on use the chromosomes from slide # 5 which show chromosomes after crossing over. The chromosomes migrate to the equator. Place them along an equator which runs from the top to the bottom of the cell. This time the homologous pairs are side by side with the equator separating the double chromosomes. This marks the end of metaphase. Answer the questions which correspond to this phase.

Anaphase I Meiosis Haploid or diploid 1n or 2n Copy the chromosomes from the previous cell and place them in this slide. The homologous chromosomes separate and migrate towards opposite sides of the cell. The sister chromatids DO NOT separate. Be sure you are deleting either haploid or diploid in each slide.

Telophase I & Cytokinesis Meiosis Haploid or diploid 1n or 2n Copy the chromosomes from the previous cell and place them in this slide. The homologous chromosomes have moved to opposite sides of the cell. They start to uncoil and the chromosomes disappear. Two new nuclear membranes form around them. Place them in the newly forming cells and draw the nuclear membranes. At this time the new nuclei contain only one of each homologous chromosome. The cells are now haploid!

Interphase Haploid or diploid 1n or 2n Copy the chromosomes from the previous cell and place them in this slide. Draw the nuclear membranes. The chromosomes do not replicate again. Answer the questions which correspond to this phase.

Prophase II Meiosis Haploid or diploid 1n or 2n Cell from the previous right Cell from previous left Copy the chromosomes from the previous cell and place them in this slide. Draw the nuclear membranes as they disintegrate. Make each of your chromosomes smaller so they fit better in the cell by selecting and then grapping a corner and making it smaller. Answer the questions which correspond to this phase.

Metaphase II Meiosis Haploid or diploid 1n or 2n Copy the chromosomes from the previous cell and place them in this slide. The nuclear membranes are gone. Line the chromosomes at the equator one above the other as in mitosis. Answer the questions which correspond to this phase.

Anaphase II Meiosis Haploid or diploid 1n or 2n Copy the chromosomes from the previous cell and place them in this slide. The sister chromatids have separated and are moving apart. The Answer the questions which correspond to this phase.

Telophase II & Cytokinesis Meiosis Haploid or diploid 1n or 2n Copy the chromosomes from the previous cell and place them in this slide. The sister chromatids have separated and are moving apart. The nuclear membrane reforms. Answer the questions which correspond to this phase.

Four gametes after Meiosis Haploid or diploid 1n or 2n Copy the chromosomes from the previous cell and place them in this slide. The new cells are now basically half a cell and can carry half of a parent’s genetic code to it’s future offspring. The Answer the questions which correspond to this phase.

Animated Version of Mitosis You are going to animate this slide. From the menu choose slide show. Choose custom animation. The blue ovals are already animated. Select play on the right side of the screen to see this. Copy your chromosomes from the metaphase slide of mitosis and place on the cell. Custom animate the chromatids so they show the process. To do this select all the chromatids on the right. Then using the window on the right click on add effect, motion paths, and then choose right. For speed select extra slow, choose start with previous. Then push play in the lower right corner of the window to see how it works. Then animate the left hand side chromatids.

Animated Version of Meiosis I Animate this slide for Meiosis I beginning at metaphase I. Copy the slide from Metaphase I of meiosis.

Animated Version of Meiosis II Animate this slide for Meiosis II beginning at metaphase II. Copy your slide of Metaphase II.

Animated Version of Meiosis I with Nondisjunction Animate this slide for Meiosis I beginning at metaphase I. Show how nondisjunction occurs. You may simply copy your other animated slide of Meiosis I and then alter the path of one double chromosome.