Meiosis Practice Ground
SC.11.04.03.01 Compares and contrasts mitosis and meiosis (CMCS 3.9)
(CAS 7.2)
This activity will help you practice the steps in meiosis. Use small pieces of
pipe cleaner to represent the chromosomes. We are going to pretend that
the parent cell only has two chromosome pairs: a red one originally
maternal, and a green one originally paternal. Each pair of chromosomes
has two parts or chromatids.
Here is the cell (actually the nucleus), please place the two chromosome
pairs in it. During the resting (this is a bad name) stage (interphase) of the
cells, the two chromosome pairs in the cell duplicated, just like they do
before mitosis. Now you have 2 times 2 pairs of chromosomes. The like
pairs stay close together. Show what this would look like:
1. The first stage in meiosis is prophase 1. In prophase, the chromosomes
that are identical stick together in places and exchange some of their
DNA. Detach a piece of one chromatid and swap it out with its
homologue:
2. The second stage of meiosis is metaphase 1. In metaphase 1, the
chromosome pairs align along the middle of the cell. One homologue
(the copied ones) on each side of the middle of the cell. Show what that
looks like:
3. Now it gets simple. The chromosome pairs let their homologues travel to
different ends of the cell. This stage is called anaphase 1.
4. In the last stage of this first meiotic division, telophase 1, two separate
cells are formed around the homologues.
There are now two cells, each with the two chromosome pairs. These two
cells are not identical because of the information exchange in prophase 1.
1. In prophase II, the chromosome pairs again line up in the middle of
their respective cells. This time they are not duplicated first.
2. In metaphase II, the centromere disappears and the chromosome pairs
are not pairs any longer.
3. In anaphase II, the chromatids move to the opposite ends of the cells.
4. In telophase II, the new cells form around the chromatids. You now
have four cells from the original one.
Look at the cells and decide if they are the same. In a female, one of
these cells would become the developing egg (the other three become
food for that egg). In a male, the four cells are sperm cells. Cool , ey?
Notice that mitosis is really no different from the second meiosis
division, except that everything is doubled.
Try this one more time, to make sure that you know what is going on.
Then make me a flip book that shows the whole process of
meiosis. Your flip book will be due at the end of the next period, so get
to work!