Lab_5 5w1w2d

Your Full Name:

UMUC Biology 102/103 Lab 5: Meiosis INSTRUCTIONS: 

On your own and without assistance, complete this Lab 5 Answer Sheet electronically and submit it via the Assignments Folder by the date listed in the Course Schedule (under Syllabus).



To conduct your laboratory exercises, use the Laboratory Manual located under Course Content. Read the introduction and the directions for each exercise/experiment carefully before completing the exercises/experiments and answering the questions.



Save your Lab 5 Answer Sheet in the following format: LastName_Lab5 (e.g., Smith_Lab5).



You should submit your document as a Word (.doc or .docx) or Rich Text Format (.rtf) file for best compatibility.

© eScience Labs, LLC 2014

Pre-Lab Questions 1. Compare and contrast mitosis and meiosis.

2. What major event occurs during interphase?

© eScience Labs, LLC 2014

Experiment 1: Following Chromosomal DNA Movement through Meiosis Data Tables and Post-Lab Assessment Trial 1 - Meiotic Division Without Crossing Over Beads Diagram:

Take pictures of your beads for each phase of meiosis I and II without crossing over. Include notes with your name, date and meiotic stage on index cards in the pictures. Insert pictures here: Prophase I

Metaphase I

Anaphase I

Telophase I

Prophase II

© eScience Labs, LLC 2014

Metaphase II

Anaphase II

Telophase I

Cytokinesis

Trial 2 - Meiotic Division Beads Diagram:

Take a picture of your results for Trial one. Include a note with your name and date and meiotic stage on an index card in the picture. Insert pictures here: Prophase I

Metaphase I

Anaphase I

© eScience Labs, LLC 2014

Telophase I

Prophase II

Metaphase II

Anaphase II

Telophase I

Cytokinesis

Post-Lab Questions 1. What is the ploidy of the DNA at the end of meiosis I? What about at the end of meiosis II?

© eScience Labs, LLC 2014

2. How are meiosis I and meiosis II different?

3. Why do you use non-sister chromatids to demonstrate crossing over?

© eScience Labs, LLC 2014

4. What combinations of alleles could result from a crossover between BD and bd chromosomes?

5. How many chromosomes were present when meiosis I started?

© eScience Labs, LLC 2014

6. How many nuclei are present at the end of meiosis II? How many chromosomes are in each?

7. Identify two ways that meiosis contributes to genetic recombination.

© eScience Labs, LLC 2014

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

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

i. Sperm Cell:

© eScience Labs, LLC 2014

ii. Egg Cell:

iii. Daughter Cell from Mitosis:

iv. Daughter Cell from Meiosis II:

10. Research and find a disease that is caused by chromosomal mutations. When does the mutation occur? What chromosomes are affected? What are the consequences?

© eScience Labs, LLC 2014

11. Diagram what would happen if sexual reproduction took place for four generations using diploid (2n) cells.

© eScience Labs, LLC 2014

Experiment 2: The Importance of Cell Cycle Control Data Tables and Post-Lab Assessment 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

© eScience Labs, LLC 2014

of the body’s natural cell cycle control proteins. This mutation resulted in cancer, 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?

© eScience Labs, LLC 2014