Download DESKTOP YARN MITOSIS/MEIOSIS SET UP AHEAD OF TIME: Cut

DESKTOP YARN MITOSIS/MEIOSIS
SET UP AHEAD OF TIME:
Cut yarn pieces and place in Zip-lock baggies. You may use whatever colors you like, but
each kind/size of yarn below needs to be a different color.
FOR THE ACTIVITY:
Each individual/group will need a Zip-lock baggie containing the following:
How many?
1
4
1
6
6
2
2
2
2
2
2
COLOR
Black
Pink
Orange
Purple
Green
Purple
Purple
Purple
Green
Green
Green
length
120”
20”
22”
15”
15”
4”
4”
2.5”
2.5”
1”
1”
Represents
Cell membrane
Nuclear membranes
Cell plate
chromatin
chromatin
Chromosomes
Chromosomes
Chromosomes
Chromosomes
Chromosomes
Chromosomes
ACTIVITY:
Walk students through the phases of mitosis and have them move the yarn pieces on their
desks as each step is discussed. After they have practiced all the phases, quiz them by
naming different phases and have them create them on their desks. Activity can be repeated
when learning about meiosis so students can see how it is different (synapses, independent
assortment, etc)
INTERPHASE: (IN between dividing) (not really mitosis
Set up cell membrane on desk (Use black string to make a big oval on the desk).
DNA will switch back and forth between chromatin (long) and chromosomes (short) pieces
during the activity.
In interphase DNA is spread out as chromatin. Cells start with 6 chromosomes.
(Count out 3 long purple and 3 long green strings and place in center of cell)
Nuclear membrane is visible (Place pink yarn piece around the DNA)
G1 phase: The period prior to the synthesis of DNA. In this phase, the cell increases in mass
in preparation for cell division
During S phase DNA is copied. Hold up each chromatin yarn piece and place a "copy" along
side of it.
G2 phase: The period after DNA synthesis has occurred but prior to the start of prophase.
The cell synthesizes proteins and continues to increase in size
(Use the 3 extra long purple/green strings)
Replace DNA in nucleus
PROPHASE: (First dividing phase- Pros are #1)
Chromatin condenses into chromosomes (Replace longer yarn pieces in nucleus with shorter
ones)
Remember to keep the chromatid "copies" together.
Nucleus/nucleolus disappears. (Remove pink yarn piece around chromosomes)
Genetic information can be swapped between chromatids. This is crossing over and results in
variation.
Images by Riedell
Centrioles/Spindle appear (play role of spindle with your fingers)
METAPHASE (MIDDLE)
Chromosomes line up in middle of cell. {Spindle (fingers) move chromosomes to middle of cell}
Chromosomes line up in a random order. Another chance for variation.
Image by Riedell
ANAPHASE (APART)
Chromatid arms separate and move to opposite ends of cell (Use fingers to separate
chromatid arms)
Image by Riedell
TELOPHASE (TWO NUCLEI)
Count chromosomes. You started with 6 (3 large, medium, small purple & 3 large, medium,
small green)
How many does your cell have now? (Should have 3 purple and 3 green; check to make sure
you have one L, M, S purple and one L, M, S, green)
Images by Riedell
Chromosomes spread back out into chromatin (Replace short yarn pieces with longer yarn
pieces)
Nucleus/nucleolus return (Put pink string around each set of chromosomes.)
Spindle/centrioles disappear.
CYTOKINESIS (Cytoplasm splits)
Animal cells use a cleavage furrow.
(Have students push cell membrane together in middle to make two cells)
Plant cells make a cell plate
(Have students use their orange string to make a wall instead of pinching)
Images by Riedell
HOW IS MEIOSIS DIFFERENT?
PROPHASE I
Homologous partners match up (synapsis) and crossing over occurs
Image by Riedell
METAPHASE I
Homologous partners line up in middle together
Image by Riedell
ANAPHASE I
Homologous partners separate/chromatids stay together
Independent assortment
Image by Riedell
METAPHASE II
Image by Riedell
ANAPHASE II
Chromatids separate
Image by Riedell
TELOPHASE II/CYTOKINESIS
Cells end up with only 3 chromosomes (one L, M, S)
Independent assortment gives different color combinations