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' DNA Replication Simulation using Pipe Cleaners
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Names:
lntroduction:
We know that DNA is found wound up in chromosomes. lt is usually found as one Iong molecule in
a single chromosome. However, whenever the cell wants to divide, the DNA, and all organelles in
the cell have to double themselves (replicaie) so that each of the two new cells (daughter cells) have
the same number of chromosomes and organelles as the mother cell. Replication occurs at the
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beginning of the cell cycle, in what is called interphase. ln this lab activity, you will simulate the
replication of DNA using pipe cleaners (as the sides of DNA) and beads (as the 4 nitrogen bases of
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DNA).
Materials:
2 pipe cleaners of one color
L pipe cleaner of another color cut in half
2 pipe cleaners of yet another color cut into 24 pieces
48 beads (4 colors are needed: L2 of each color would make it exactly even but you could have 20
of two colors and 4 of two others, 1"6 of two and 8 of two others, etc.)
Purpose:
To understand the process of Replication in the nucleus at the beginning of cell division.
Procedure:
1. Obtain all of the materials listed above and cut two pipe cleaners of the same color into 24
pieces. You will have to figure out how to do this evenly!
2.
With the two long pipe cleaners of the same color, start putting
beads on it using two beads to represent one base. You can use any
order that you like, but write your code in the box to the right. Be
sure to space the beads (base pairs) about one inch apart. The bead
go on the small pipe cleaner pieces. Look at the drawing to the
right to see how it should look.
Remember: "A" goes with'T'and "C" goes with "G".
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5. You will attach new bases to the lonely
bases who have lost
partners.
attach
beads
onto the waiting
To simulate this,
their
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pipe cleaner and then attach the half size pipe cleaner to the
side to simulate the new side of DNA. (see drawing to the
right).
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6. Show your
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completed molecule
to your teacher for a stamp.
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lmagine that the DNA continues to unzip al! the way up untill
the entire DNA molecule has been copied.
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Now, after you have made a piece of DNA that is 4 rungs of the
ladder (4 base pairs), you will simulate that the DNA unzips by pulling
apart the big pieces of pipe cleaner. Each side will have a base that
has lost it's partner to the other side. (see drawing to the right)
4.
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