Name: _______________________________________________
Class: ______________
Mitosis Intro Video
https://www.youtube.com/watch?v=gwcwSZIfKlM
Directions: Please answer the following questions while watching the mitosis video.
1. TRUE or FALSE (circle one): Mitosis makes sperm and egg cells.
2. Mitosis is only done by _____________________ cells and it makes ___________________________ cells.
3. __________________________ is uncontrolled cell growth.
4. TRUE or FALSE (circle one): Cells spend about 90% of time in interphase, and only 10% in
mitosis.
5. Chromosomes are made of ______________ and ___________________________.
6. Humans have ___________ chromosomes in a cell.
7. Because prophase is the first step of mitosis, the ______________________ is still there.
8. In metaphase, the chromosomes line up in the ________________________ of the cell.
9. The nucleus disassembles during ________________________________.
10. ____________________ are fibers that help move chromosomes to opposite ends in anaphase.
11. The last stage of mitosis is telophase and new __________________ are forming on each side to
make two new cells.

However, the two cells do not completely separate until after mitosis, during
cytokinesis!
Look at the cells (numbered 118), and write which numbers
on the lines below for which
stage you think that cell is in.
Interphase: ________________________
Prophase: ________________________
Metaphase: ________________________
Anaphase: ________________________
Telophase: ________________________
Mitosis Coloring Activity
Directions: Read through the information below, then answer the questions that follow and color the
diagram as indicated in the questions. You will need markers or colored pencils to complete this activity.
Many, many years ago (actually probably around 13-14 years ago), you were made of just one cell. Just
one tiny cell that people needed a microscope to see. Then, one day, that cell underwent mitosis, which
means cell division. Everything inside that cell was copied (the nucleus, the mitochondria, the vacuoles,
all the DNA, etc.) so that when the cell split, both the new cell and the old cell would have everything they
needed to survive. These two cells then each underwent mitosis so that these two became four cells, and
those four cells became eight, and then sixteen cells, and then thirty-two cells and so on. Eventually,
there enough cells so that a beautiful bouncing baby was born (that’s you). But it didn’t stop there! You’d
look pretty funny as a 10 pound 8th grader, so instead your cells continued going through mitosis making
more and more cells. That’s why you are bigger today than when you were born. You have more cells
(but NOT bigger cells) than when you were a baby. Elephants have more cells than you do, but the cells
they have are about the same size as yours.
Louis Pasteur taught us that no living thing, not even cells or bacteria, can pop into being out of nowhere.
Everything has to come from somewhere; every living thing has to have parents of some kind. All living
things are made of cells, and all cells come from other cells. So as you can see, mitosis is the basis of all
life! Let’s find out how it works.
Mitosis is a process that can be broken down into 4 steps. These steps are called Prophase, Metaphase,
Anaphase, and Telophase. A phase called interphase is not actually part of mitosis, but is the resting phase
that the cell is in when it is not dividing. Cytokinesis is a phase that happens after mitosis during cell
division.
Interphase. Most of the time, a cell is not actually dividing. Instead it spends most of its time just resting
and performing cell activities like cellular respiration, osmosis, and for plant cells, photosynthesis.
During interphase, DNA and other cell materials are copied. While in interphase, the DNA is shaped like
uncoiled strands that look like spaghetti. When it is in this shape, it is called chromatin. When DNA is
loosely packed like this, it is much easier for the cell’s machinery to copy.
Prophase. This is the first step of mitosis. The nuclear membrane (membrane around the nucleus)
breaks apart. Chromatin condenses into rod-like structures called chromosomes. Take a look the next
page and find something inside any of the cells that looks like a big fat X. This is a chromosome that has
been copied. One half of the X is the original chromosome and the other half is the copy. Another thing
that happens during Prophase is that the centrioles move to opposite sides of the cell, and spindle fibers
form across the cell. We’ll find out what these do later.
Metaphase. During this stage of mitosis, the chromosomes line up in the middle of the cell, right along
the center “line” (which is invisible). Each chromosome attaches itself to a spindle fiber.
Anaphase. The centrioles act like fishermen and start to reel in their fish (the chromosomes) using the
spindle fibers as line. During anaphase, the twin copies of the chromosomes get separated and each copy
moves to opposite sides of the cell. The chromosomes move away from the middle.
Telophase. Now that the chromosomes are separated, two new cells are formed. The spindle fibers
disappear; the chromosomes uncoil and become spaghetti-like chromatin again. The nuclear membrane
reappears and finally the cytoplasm divides to form two new daughter cells which are identical to each
other. In a plant cell, a cell wall forms between the two new cells.
Cytokinesis. During cytokinesis, the cell membrane pinches inward, until it eventually pinches all the
way through. It divides the parent cell’s cytoplasm into two identical daughter cells.
Questions: Answer these questions by following the directions in each one and using the pictures on the
back this page. You will need markers or colored pencils to complete this activity. The questions do not
necessarily go in order.
1. Outline the cell membrane of the cells in these colors:
Prophase cells—red
Metaphase cells—green
Anaphase cells—yellow
Telophase cells—orange
Interphase cells—purple
2. What is the name for the resting period between cell divisions? __________________________________.
Color the word brown.
3. In interphase, the DNA is in the form of loose threads called ___________________________. Color the
word and pictures blue.
4. Condensed DNA is called _______________________________. Color the word and these structures in
metaphase cells green.
5. During metaphase the chromosomes line up along the middle of the cell called the
_______________________. Write the answer in the top left corner on the other side of this paper.
6. During what stage do the chromosomes pull apart? ___________________________. Color the word
yellow.
7. Another name for cell division is ______________________________. Color the word blue.
8. What structure reappears during telophase? _____________________________________________ Outline this
structure in the telophase cells with red.
9. During which stage does the DNA copy itself? ____________________________________. Draw an orange
star next to this word.
2 NEW DAUGHTER
CELLS ARE FORMED