Lab 3 Mitosis and Meiosis Notes From the teacher

Day 1: Before class: Read pages 29-34 of the lab. Complete the pre-lab for Day 1. Pre-Lab:

1. Name 4 reasons why cells undergo mitosis. 2. Why do cells undergo meiosis? 3. Using a prepared slide of an onion root, where would you expect to see the most cells

undergoing division? 4. What is a blastula? (Should remember from Biology) 5. What do you expect to see in cells in Interphase? 6. How will you know that cells are in Prophase? 7. What do cells look like in Metaphase? 8. What do they look like in Anaphase? 9. How can you tell if cells are undergoing Telophase? 10. If you count 90 cells and 30 of them are in prophase, what is the % of cells in prophase? 11. If that particular cell takes 60 minutes to undergo mitosis then how much time do you expect

that it would spend in prophase? 12. If you found 5 cells out of 100 cells undergoing metaphase, then what is the % of cells in

metaphase? 13. If that cell type usually takes 120 minutes to undergo mitosis, then how long do you think it

must take to undergo metaphase? 14. What are two differences between cell division in plant and animal cells. (Should remember

from Biology) In class:

Complete exercise 3A.1 and 3A.2. Record all results in your lab notebook. Complete the Analysis Questions.

Day 2: Before class: N/A In class:

Complete exercise 3B.1. Record all results in your lab notebook. Complete the Analysis Questions.

Day 3: Read pages 40-44 of the lab. Complete the pre-lab for Day 3. Before class: N/A Pre-Lab:

1. Meiosis increases genetic variation in a population. Each diploid cell undergoing meiosis can produce 2n different chromosomal combinations where n is the haploid or monoploid number.

a. If you have a diploid cell with only 8 chromosomes, how many different chromosome combinations are possible due to independent assortment? (Be sure to write the formula and show your work).

b. Humans have a haploid number of 23. What is the theoretical number of chromosome combinations possible each time one of our cells undergoes meiosis due to independent assortment?

2. What is Sordaria fimicola? 3. Review the life cycle of Sordaria fimicola and explain it in words. 4. Tell if each combination of spores described below is indicative of a crossed over or non-

crossed over state: a. 8 spores in a 2 tan : 2 wild type : 2 tan : 2 wild type pattern. b. 8 spores in a 4 tan : 4 wild type pattern c. 8 spores ina 2 tan : 4 wild type : 2 tan pattern.

5. If genes cross over 20% of the time, then how many map units must separate the two genes?

In class:

Complete exercise 3B.2. Record all results in your lab notebook. Complete the Analysis of Results.