Meiosis Yarn ModelName ______

Purpose: To demonstrate meiosis by constructing a model.

Materials: yarn of two different colors, light construction paper, scissors, tape, ruler

Procedure:

  1. Fold your paper into 8 different squares.
  1. Title the paper meiosis (no larger than 1 inch).
  1. Cut a 24 inch piece of yarn in a color of your choice.**You should keep a little extra yarn.
  1. Repeat with a different color. (Don’t pick two colors that are close together like black and purple.)
  1. Cut each piece of yarn so you have

(16) two inch pieces of color one.(16) 1inch pieces of color one.

(16) two inch pieces of color two.(16)1 inch pieces of color two.

  1. Label each phase of meiosis in order going across your folded paper (no larger than 1 inch).

Prohphase I, Metaphase I, Anaphase I, Telophase/Cytokinesis I

Prohphase II, Metaphase II, Anaphase II, Telophase/Cytokinesis II

  1. Using a large Petri dish, draw 1 large cell in Prophase I, Metaphase I, and Anaphase I.
  1. Using a medium Petri dish draw 2 medium cells in Telophase/Cytokinesis I, Prophase II, Metaphase II, and

Anaphase II.

  1. Using a quarter or rubber stopper draw 4 small cells in Telophase/Cytokinesis II.
  1. Draw a nuclear membrane, nucleolus, centrioles and spindle fibers in the appropriate cells.
  1. Label the structures in step 10 in Prophase I ONLY.
  1. Using yarn as your chromosomes, and a diploid number of 4, show what happens in meiosis. Be sure to have one chromatid of each color crossing over shown all of the way through. Be consistent. If crossing over occurred in the top cells in Meiosis I that you maintain it in the top cells in Meiosis II. You can show crossing over by removing a small piece of yarn from the opposite color and taping it onto the respective chromosome.
  1. Construct 2 tetrads (1 large and 1 small) in Prophase I . Show crossing over of the larger chromosomes only. Label the tetrad and crossing over in Prophase I
  1. Draw and label the equator in Metaphase I. Line up Tetrads on the equator.
  1. Label a chromatid in Metaphase I.
  1. In telophase II, label the 4 haploid cells & write they are genetically different. Show the correct chromosomes in each cell.

NAME: ______

ANALYSIS QUESTIONS

  1. Describe two similarities in the process of mitosis and meiosis.
  1. Describe two differences between the processes of mitosis and meiosis.
  1. How many cells are created from one original cell in meiosis? ______

4(a). What is a tetrad?

(b). When do tetrads form in meiosis? ______

5(a). What is crossing over?

(b). What is its significance?

6. If a cell had 46 chromosomes, how many chromosomes would each of the four new cells contain after meiosis has occurred? ______

7. In your body, what cells are being created through the process of meiosis? ______