**Investigation 1:**

**Part 1: Modeling Mitosis**__If a model of mitosis is built out of oreo cookies then each phase can be correctly displayed using sprinkles as chromosomes, the cream as cytoplasm, and the cookie itself as the cell.__

**Hypothesis:**

**Materials:**

- Four oreos
- Lots of sprinkles
- Data table

**Procedures:**1. Take a picture of one of the oreo cookies. Then take another cookie and place it on top of the original to show how the cell grows during the first stages of interphase. Take a picture.

2. Gently twist one of the cookies apart so that you have one of the cookie sides with cream and the half side without cream.

3. Each cookie represents a cell; ice cream sprinkles represents chromosome pairs.

4. Put sprinkles (chromosomes) all scrambled in the middle of the cookie side with cream to show the first part of interphase where the DNA is tangled and coiled. Take a picture. Spread out the sprinkles on the cookie to show unraveling DNA still in interphase. Take a picture.

5. Match up the sprinkles (chromosomes) with one another sprinkle of the same color to show replication which is prophase. Take a picture.

6. Aline the sprinkles in middle of the oreo(cell) to demonstrate metaphase. Take a picture.

7. Separate the paired sprinkles to opposite sides of the oreo to demonstrate pulling of chromosomes by spindle fibers in anaphase. Take a picture.

8. Break the oreo in half with half of the sprinkles on one side and the rest on the other. This stage shows telophase as the cells splits to form a daughter cell. Take a picture.

9. Gently twist two other cookies apart so that you have one of the cookie sides with cream and the half side without cream.

10. Spread the amount of sprinkles from the split cookie in Step 8 on each new cookie with cream side. (If your original cookie had 9 pairs then the two new cookies should have one sprinkle from each pair.)

**Analysis Questions:**- Identify 1 step in your model where a mistake could occur. Describe the consequences of that mistake on the cell and on the organism.

- Describe the limitations of your model versus observing this in the real world.

__Mitosis is the process made to create the necessary cells when others die of or need replacement. It has six phases with four checkpoints to make sure that mistakes weren’t made. However in my diagram makes could have been made when not displaying spindle fibers to show how they connect to the chromatids. Also to show that the chromatids do not simply just split apart but are forced that way. In the end my hypothesis was supported mitosis was fully diagrammed using oreos cookies.__

**Conclusion:**

1. Take a picture of one of the oreo cookies. Then take another cookie and place it on top of the original to show how the cell grows during the first stages of interphase. Take a picture.

2. Gently twist one of the cookies apart so that you have one of the cookie sides with cream and the half side without cream.

3. Each cookie represents a cell; ice cream sprinkles represents chromosome pairs.

4. Put sprinkles (chromosomes) all scrambled in the middle of the cookie side with cream to show the first part of interphase where the DNA is tangled and coiled. Take a picture. Spread out the sprinkles on the cookie to show unraveling DNA still in interphase. Take a picture.

5. Match up the sprinkles (chromosomes) with one another sprinkle of the same color to show replication which is prophase. Take a picture.

6. Aline the sprinkles in middle of the oreo(cell) to demonstrate metaphase. Take a picture.

7. Separate the paired sprinkles to opposite sides of the oreo to demonstrate pulling of chromosomes by spindle fibers in anaphase. Take a picture.

8. Break the oreo in half with half of the sprinkles on one side and the rest on the other. This stage shows telophase as the cells splits to form a daughter cell. Take a picture.

9. Gently twist two other cookies apart so that you have one of the cookie sides with cream and the half side without cream.

10. Spread the amount of sprinkles from the split cookie in Step 8 on each new cookie with cream side. (If your original cookie had 9 pairs then the two new cookies should have one sprinkle from each pair.)

11. Using the two cookies last used in Step 10 repeat Steps 5 through Step 8.

12. Once you have two cookies sides split in half to make four pieces, gently twist four other cookies apart and sprinkle on the creamed sided the same amount of sprinkles used in your last division of cookie cells.

**Part 2: Modeling Meiosis**__: If a model of meiosis is built out of oreo cookies then each phase can be correctly displayed including the first rounds of prophase, metaphase, anaphase, telophase, and cytokinesis as well as the second round.__**Hypothesis****Materials:**- Six oreos
- Lots of sprinkles
- Data table

**Procedures:**1. Take a picture of one of the oreo cookies. Then take another cookie and place it on top of the original to show how the cell grows during the first stages of interphase. Take a picture.

2. Gently twist one of the cookies apart so that you have one of the cookie sides with cream and the half side without cream.

3. Each cookie represents a cell; ice cream sprinkles represents chromosome pairs.

4. Put sprinkles (chromosomes) all scrambled in the middle of the cookie side with cream to show the first part of interphase where the DNA is tangled and coiled. Take a picture. Spread out the sprinkles on the cookie to show unraveling DNA still in interphase. Take a picture.

5. Match up the sprinkles (chromosomes) with one another sprinkle of the same color to show replication which is prophase. Take a picture.

6. Aline the sprinkles in middle of the oreo(cell) to demonstrate metaphase. Take a picture.

7. Separate the paired sprinkles to opposite sides of the oreo to demonstrate pulling of chromosomes by spindle fibers in anaphase. Take a picture.

8. Break the oreo in half with half of the sprinkles on one side and the rest on the other. This stage shows telophase as the cells splits to form a daughter cell. Take a picture.

9. Gently twist two other cookies apart so that you have one of the cookie sides with cream and the half side without cream.

10. Spread the amount of sprinkles from the split cookie in Step 8 on each new cookie with cream side. (If your original cookie had 9 pairs then the two new cookies should have one sprinkle from each pair.)

11. Using the two cookies last used in Step 10 repeat Steps 5 through Step 8.

12. Once you have two cookies sides split in half to make four pieces, gently twist four other cookies apart and sprinkle on the creamed sided the same amount of sprinkles used in your last division of cookie cells.

**Analysis Questions:**- Identify 1 step in your model where a mistake could occur. Describe the consequences of that mistake on the organism's possible progeny.

- Compare and Contrast the process of mitosis and meiosis.

__Mitosis and meiosis are much the same processes. Both create more cells in the body through cell division. However in meiosis it is for reproduction and mitosis is for the good of the body. If new skins cells are needed mitosis will occur. On the other hand in reproduction in sperm or eggs meiosis is needed to create genetic diversity. Both processes have the same steps but meiosis is doubled and therefore longer.__

**Conclusion:**

**Investigation 2:**

__If it takes onion root tips twenty four hours to complete the cell cycle slowly then it will take each phase at least sixty minutes.__

**Hypothesis:**

**Materials:**- Link for the online lab
- Calculater

__: *Note: The actual lab failed to produce any results so an online lab was used for this Investigation.*__

**Procedures**- Click on the given link. Time Spent in the Phases of Mitosis
- Put the given cells into the phase they belong in as they are given to you.
- Count the amount of cells in each phase and record it in the data table.
- Calculate the number percent of cells in each phase using the number of cells in that phase and the amount of cells total. Record in the data table.
- Calculate the time spent in each phase by doing: % of cells stage X 1440 minutes. Record in the data table.

**Analysis:**- To calculate the amount of time spent in each phase of the cell cycle from the percentage of cells in that stage. On the average, it take 1,440 minutes (24 hours) for onion root tip cells to complete the cell cycle.

__In conclusion, although my hypothesis was correct it was also incorrect and vague. It was incorrect because telophase did not take sixty minutes, it only needed 38.8 minutes, but was correct because all other phases took longer than sixty minutes to be completed. My hypothesis supported all but one phase. However, errors could have been made when calculating the percent total of cells counted because when I rounded off I did not increase the last digit only kept it the same. So when calculating the time spent in the phase my numbers might have been slightly different than what is fully correct.__

**Conclusion:**

**Investigation 3:**Based on your knowledge about human chromosomal disorders and nondisjunction due to loss of control during the cell cycle, identify the name of the syndromes and karyotypes of the following patients.

*Note: The picture on the right is of normal chromosomes from a male and female captured in metaphase and is used as a point of reference.*

**Conclusion:**Any variations missing or extra chromosomes significantly affects a person. In all of the patient's chromosomes see above the addition of one single chromosome resulted in a defect in their genes. Each have a specific syndrome determined by whichever chromosome they have an extra of. Having an extra 21 chromosome resulted in Down Syndrome. An extra copy of chromosome 18 creates Edwards Syndrome. If everything in the chromosomes are not exactly right as a result syndromes can be seen.

**Investigation 4: Meiosis & Crossing Over**Study the pictures of Sordia in the picture below by counting at least 50 asci and scoring them as either parental or recombinant.

- If the ascospores are arranged 4 dark/4 light, count the ascus as “No crossing over.”
- If the arrangement of ascospores is in any other combination, count it as “Crossing over.”
- Record your results in the data table provided.

**Analysis Questions:**- Once you have determined if crossing over has occurred in at least 50 hybrid asci, record your data in the table below.
- Based on your counts, determine the percentage of asci showing crossover. Record in the table below.
- Divide the percent showing crossover by 2. This is your gene to centromere distance. (The percentage of crossover asci is divided by 2 because only half of the spores in each ascus are the result of a crossover event.)

__In conclusion it is shown that about fifty percent of Asci crossover. Majority of the Asci had the four dark four light combination that were parental. Many others however were a mixture of of light and dark. Mistakes happened when counting. It was assumed that any presence of four light and four dark ascospores were parental and did not cross over. The correct show of no crossing over must be arranged four light and four dark or vice versa. That was not counted in that way during the experiment so my numbers showing how many crossing over and how many are not are incorrect.__

**Conclusion:**