Straighterline BIO201LLab 3 Mitosis and Meiosis

Student Name: Lindsey Magee

Access Code (located on the lid of your lab kit):AC-WU31YKO

Pre-Lab Questions

1.            What are chromosomes made of?

2.            Compare and contrast mitosis and meiosis.

3.            Cancer is a disease related to uncontrolled cell division. Investigate two known causes for these rapidly dividing cells and use this knowledge to invent a drug that would inhibit the growth of cancer cells.

Experiment 1: Observation of Mitosis in a Plant Cell

Table 1: Mitosis Predictions

Predictions        

Supporting Evidence     

Table 2: Mitosis Data

 Chosen Image                                 

Stage                     Number of Cells in Stage              Total Number of Cells                    Calculated % of Time Spent in Stage

Interphase                          18                                                           25                                                           72%

Prophase                             2                                                              25                                                           8%

Metaphase                         0                                                              25                                                           0%

Anaphase                            1                                                              25                                                           4%

Telophase                           2                                                              25                                                           8%

Cytokinesis                         2                                                              25                                                           8%

 Table 3: Stage Drawings

Cell Stage            Drawing

REMEMBER: Your drawings should have your name and access code handwritten in the background.

Interphase         

 Prophase           

 Metaphase       

 Cell Stage           Drawing

REMEMBER: Your drawings should have your name and access code handwritten in the background.

Anaphase           

 Telophase         

 Cytokinesis       

 Post-Lab Questions

1.            Label the arrows in the slide image below with the appropriate stage of the cell cycle.

A-

B-

 C-

 D-

E-

F-

 2.           What stage were most of the onion root tip cells in? Why does this make sense?

3.            As a cell grows, what happens to its surface area : volume ratio? (Think of a balloon being blown up). How is this changing ratio related to cell division?

4.            What is the function of mitosis in a cell that is about to divide?

5.            What would happen if mitosis were uncontrolled?

6.            How accurate were your time predictions for each stage of the cell cycle?

7.            Discuss one observation that you found interesting while looking at the onion root tip cells.

Experiment 2: Tracking Chromosomes Through Mitosis

Once you have completed the digital exercise, select the “Results Table” button at the bottom right-hand corner of the screen and select the “Generate PDF” button at the top of the following screen. Insert your download into this document by selecting the Insert > Object > Text from file. Resize if necessary.

Post-Lab Questions

1.            How many chromosomes were present before mitosis?

2.            How many chromosomes did each of the daughter cells contain after mitosis?

3.            Cite an example of a type of cell that undergoes mitosis. Why is it important for each daughter cell to contain information identical to the parent cell?

4.            Human skin cells divide at a higher rate than neurons (nerve cells). Hypothesize why this may be.

5.            Hypothesize what would happen if the sister chromatids did not split equally during anaphase of mitosis.

 

Experiment 3: Following Chromosomal DNA Movement through Meiosis

Part 1: Once you have completed the digital exercise, select the “Results Table” button at the bottom right-hand corner of the screen and select the “Generate PDF” button at the top of the following screen. Insert your download into this document by selecting the Insert > Object > Text from file. Resize if necessary.

Parts 2, 3, and 4: Once you have completed the digital exercise, select the “View Data Table” button at the bottom left-hand corner of the home screen. Review your table. If you would like to make any changes, select the “Return” button in the bottom right-hand corner. If you are satisfied with your answers, select the “Generate PDF” button at the top of the screen. Insert screenshots below. Resize if necessary:

 Post-Lab Questions

1.            How did crossing over affect the genetic content in the gametes? Use your results to support your answer.

2.            What is the ploidy of the daughter cells at the end of meiosis I? What about at the end of meiosis II?

3.            List two differences between meiosis I and meiosis II.

4.            Based on your observations in the digital exercise, what can you conclude about the severity of nondisjunction that occurs in meiosis I as opposed to meiosis II?

5.            Why is it necessary to reduce the number of chromosomes in gametes, but not in other cells?

6.            Blue whales have 44 chromosomes in every cell. Determine how many chromosomes you would expect to find in the following:

Sperm Cell:

 Egg Cell:

Daughter Cell from Mitosis:

Daughter Cell from Meiosis II:

Experiment 4: The Importance of Cell Cycle Control

Data:

1.           

2.           

3.           

4.           

5.           

Post-Lab Questions

1.            Record your hypothesis from Step 1 in the Procedure section here.

2.            What do your results indicate about cell cycle control?

3.            Suppose a person developed a mutation in a somatic cell which diminishes the performance of the body’s natural cell cycle control proteins. This mutation resulted in cancer yet, but was effectively treated with a cocktail of cancer-fighting techniques. Is it possible for this person’s future children to inherit this cancer-causing mutation? Be specific when you explain why or why not.

4.            Why do cells which lack cell cycle control exhibit karyotypes which look physically different than cells with normal cell cycle.

5.            What are HeLa cells? Why are HeLa cells appropriate for this experiment?

6.            Research the function of the protein called p53. What does this function do? Explain how it can affect cell cycle control.

7.What is the Philadelphia chromosome? How is this chromosome related to cancer? Identify how this chromosome appears physically different on a karyotype than it appears on a karyotype of normal chromosomes.