Name ____________________________________________________
Date ________
Activity: A Model of Meiosis
Goal: To model the steps in the process of meiosis.
Background Information: How do sex cells end up with half the
number of chromosomes as body cells? To answer this question you
need to understand the events that occur during meiosis. Meiosis
(my OH sis) is the process by which the number of chromosomes is
reduced by half to form sex cells –sperm and eggs. The basic steps
of meiosis are as follows:
In the beginning of meiosis, every chromosome in the cell is copied.
During Meiosis I, double stranded chromosomes separate and two cells form, each
with half the number of chromosomes.
During Meiosis II, the double stranded chromosomes split and move to opposite ends
of the cell.
At the end of meiosis, four sex cells are produced. Each sex cell has half the
number of chromosomes that the parent cell had at the beginning of meiosis.
Only one chromosome from each chromosome pair is found in each sex cell. When sex
cells combine to produce offspring, each sex cell will contribute half the number of
chromosomes. Therefore each offspring gets the normal number of chromosomes – half
from each parent. (This information is from Science Explorer, TE)
Materials: Meiosis template (a large sheet with circles), 4 red pipe cleaner pieces, 4
white pipe cleaner pieces
Procedure:
1. What I Know: Write a sentence or two about what you already know about
meiosis.
2. Work with a partner. Arrange four pipe cleaners, 2 white and 2 red, randomly
inside the first (top) single circle on the Meiosis template. This circle represents a
parent cell about to undergo meiosis. The pipe cleaners represent 2 pairs of
chromosomes.
3. In the second single circle, place another white pipe cleaner next to each of the
white ‘chromosomes.” Place another red pipe cleaner next to each red
“chromosome” These pipe cleaners represent doubled chromosomes in the first
step of meiosis.
4. Now find the 2 circles side by side on the Meiosis template. These circles
represent the 2 new cells produced during the first cell division of meiosis. Divide
the doubled “chromosomes” equally between the 2 NEW cells. Place them in the
2 circles on the Meiosis template.
5. Now locate the 4 circles that are side by side on the blue sheet. These circles
represent the sex cells that are the product of the second cell division of meiosis.
Divide the pipe cleaners EQUALLY to represent the “chromosomes” present in
the sex cells. Place the pipe cleaners in the 4 circles on the Meiosis template.
6. What I Did: Write a summary of the procedure you used to create the model of
meiosis.
7. What I Observed: Make a drawing of the model you created.
A Model of Meiosis
8. What I Learned: Write a complete explanation of what you learned about
meiosis from completing this activity.
9. What I Wonder: Pose a question about what you may still like to know about this
topic.
10. Questions: Answer the following questions in complete sentences.
a. How many divisions take place in meiosis?
b. How many chromosomes did your model start out with in each cell?
c. How many chromosomes did your model end up with in each cell?
d. If an organism has 16 chromosomes, how many will it have in each sex
cell after meiosis?
e. How is meiosis different from mitosis?
f. In your own words, write a summary of the process of meiosis.