Download Understanding Mitosis

Chanda Robinson
Mitosis vs Meioses
How to Use this Tutorial
Hello students today’s tutorial is to understand the difference in Mitosis and Meiosis also known as asexual and
sexual cell reproduction. To find your way through this tutorial, is easy. You will use your mouse to click on
the buttons at the bottom of the screen:
To return to the beginning of the tutorial, click
on the Home button.
To go to the previous page click the arrow pointing
To move to the next page, click the next arrow
button.
You will hear a click each time you click your mouse on the arrow.
There will be self checks along the way to evaluate (check for understanding) your progress.
Happy Learning
Understanding Mitosis
Mitosis is defined as the process, in the cell cycle, by which a cell duplicates into two genetically identical daughter
homologous cells. This means that the cells has the same shape, same types of genes in the same location,
everything matches up. In mitosis, chromosomes in the cell nucleus are separated into two identical sets of
chromosomes, each in its own nucleus..
The best way to remember the phases of Mitosis is to create an Acronym. Below is an
acronym to help you remember the correct order of mitosis. However one will still
need to know what happens in each phase to identify the difference in mitosis and
meiosis the two process in cell division.
Interphase = In
Prophase= Professional
Mataphase = Martial
Anaphase = Arts you
Telephase = Take
Cytokinesis= Chances
Now that I know the phases what all is involved in mitosis?
Understanding Mitosis Cont.
One single stain of DNA is called a haploid- when a cell has only one set of chromosome. That single strain of DNA
can also be called a chromatid or a gametes in sex cells. In the second picture there are two stains of DNA which
are twisted together which is called a diploid. When two gametes form a diploid zygot they have (2n) which is twice
the number of chromosomes. Another example of how this DNA looks is below.
A cell has a certain number of chromosomes. Each strain or chromatid is held together by a little circle in the
middle called a centromere .
How does this fit in with mitosis?
.
Understanding Mitosis Cont.
Another way to remember information concerning mitosis is that it has to be with my body. These cells regenerate to
help the body heal and repair itself. So if you scrape your knee skin cells are going to reproduce themselves to heal your
scraped knee. It will reproduce the same exact cell over and over until your knee is healed. Meaning it will look like it did
before you hurt yourself. Below are the phases of mitosis and what each stage looks like. The colored picture is the end
result of mitosis.
Interphase is the first phase and the longest phase of the cell cycle. This is the stage where DNA copies itself. The cell is
growing during this stage During the next the chromatin condenses into double rod-shaped structures
called chromosomes in which the chromatin becomes visible. This is called Phrophase. Next is Metaphase where the
chromatin align in the middle of the cell. The spindle fibers attach to the centromeres that hold the chromatids together.
This is the process before the separation into two daughter cells. Next during Anaphase the chromosomes break at the
centromeres. Basically there are pulled apart this is the shortest phase of Mitosis. The next to the last phase is called
Telophase when the nuclear membrane re-forms around the chromosomes. The nucleolus reforms and the cell begins
to split into two cells. Lastly two new daughter cells are created and this stage is called cytokinesis.. See below for each
step and phase.
Check for understanding
Before we move on to sexual reproduction or meiosis let’s check to make sure we are on track.
A.
Asexual Reproduction will result in
1. 2 cells with the same DNA
2. 1 cell with different DNA
3. 2 new cells with totally different DNA in each cell
4. A cell
B. A single strain of DNA is called a
1.A zygot
2.A chromatid
3.Cell
4.Sex cell
C. The correct order of Mitosis is
1.Cytokinesis, Anaphase, Telephase, Prophase, Paraphrase and Interphase
2.Interphase, Prophase, Cytokinesis, Telephone, Anaphase and Mataphase
3.Interphase, Prophase, Metaphase, Anaphase, Telephase and Cytokinesis
4.Prophase, Interphase, Anaphase, Metaphase, Cytokinesis, and Telephase
Check for understanding
Before we move let’s make sure that you selected the correct answers to the questions. The correct
answer is written in red.
A.
Asexual Reproduction will result in
1. 2 new cells with the same DNA
2. 1 cell with different DNA
3. 2 new cells with totally different DNA in each cell
4. A cell
B. A single strain of DNA is called a
1.A zygot
2.A chromatid
3.Cell
4.Sex cell
C. The correct order of Mitosis is
1.Cytokinesis, Anaphase, Telephase, Prophase, Paraphrase and Interphase
2.Interphase, Prophase, Cytokinesis, Telephone, Anaphase and Mataphase
3.Interphase, Prophase, Metaphase, Anaphase, Telephase and Cytokinesis
4.Prophase, Interphase, Anaphase, Metaphase, Cytokinesis, and Telephase
How did you do? Great lets move on
Understanding Meiosis
The process of meiosis produces two daughter cells from a parent cell. An easy way to look at this is to think of you. In order to
create you there was a mom and a dad which are called parents. In meiosis a mom cell which has ½ of the DNA and the dad
cell has ½ of the DNA. During meioses there will be a unique (not identical) cell created from the parent cell. Think about
your brothers and sisters although you may have the same parents you have a unique (not like theirs) appearance. Because
there is a mom and dad cell that produce an offspring these are called sex cells or gametes (i.e. eggs and sperm). Because
they are produced from sperm cells, gametes are likewise haploid. At the end of this process there should be four unique
daughter cells created.
Unlike mitosis meioses does not begin at interphase. That step has already been complete in the parent cell before reproduction
begins. Since Meiosis needs two cells all of the steps of mitosis have already taken place. In meioses there are not any new
phase names just replications of the mitosis steps but happening at the same time in two parent cells. Therefore after
Interphase, Prophase, Metaphase, Anaphase, Telephase and Cytokinesis the phases continue with Prophase II, Metaphase II,
Anaphase II, Telephase II and at the end of these phases there are 4 hypoid cells created.
But what happens during each phase ?
Understanding Meiosis Cont.
To remember the phases of Meiosis this acronym may help:
Prophase II= Please
Mataphase II = Make
Anaphase II = Anchovie
Telephase II = Tacos
During Prophase II the chromosomes will not copy in further, however the spindle fibers appear and the nuclei
and nuclear membranes have broken apart. In Metaphase II the chromosomes begin migrating (moving)
to the equator (the middle) of both cells. Once the chromosomes have lined up at the cell’s center the
fibers of the sister chromtaids (remember that is a part of a chromosome) begin to point towards the
opposite poles. The sister chromtaids separate (break apart) and start to migrate to the ends of both cells
anaphase II is complete. At this time each is now a chromosome and the new cells are ready to begin to
split. In telophase II The nuclui has formed around each new chromosome and four haploid (single stain of
DNA) cells have been formed.
Check for understanding
1.
What phases do not occur during Meiosis?
a. Phropase II
b. Interphase and Cytokensis
c. Metaphase and Anaphase II
d. Telophase II and Metaphase II
2. How many cells will be created at the end of Meiosis
a. 4 hyploid unique cells
b. 4 heterogeneous cells
c. 3 chromosomes cells
d.
2 chromtaid cells
3. During Meioses the nuclui does not form around new cells.
a.True
b.False
c. Not sure
D, What is a nuclui?
4. A _______ is a sex cell?
a. Gamete
b. Hyploid
c. Egg
d. Centromere
Let’s see what you got right
l
Checking for understanding cont.
1. What phases do not occur during Meiosis?
a. Phropase II
b. Interphase and Cytokensis
c. Metaphase and Anaphase II
d. Telophase II and Metaphase II
2. How many cells will be created at the end of Meiosis
a. 4 hyploid unique cells
b. 4 heterogeneous cells
c. 3 chromosomes cells
d. 2 chromtaid cells
3. During Meioses the nuclui does not form around new cells.
a.True
b.False
c. Not sure
D, What is a nuclui?
4. A _______ is a sex cell?
a. Gamete
b. Hyploid
c. Egg
d. Centromere
I know that you got them all right. Lets look at a quick review.
One last check for understanding cont.
1. Mitosis cell division is asexual reproduction ?
a. fales
b. true
c. Could be
d. Maybe note
2. Production of a unique cell is done during
a. meiosis
b. interphase
c. chromsome
d. mitosis
3. Mitosis helps to heal my body.
a.True
b.False
c. Not sure
D, What is a mitosis?
4. A _______ is a body cell?
a. somatic
b. Hyploid
c. Egg
d. Centromere
One last check for understanding cont.
1. Mitosis cell division is asexual reproduction ?
a. fales
b. true
c. Could be
d. Maybe note
2. Production of a unique cell is done during
a. meiosis
b. interphase
c. chromsome
d. mitosis
3. Mitosis helps to heal my body.
a.True
b.False
c. Not sure
D, What is a mitosis?
4. A _______ is a body cell?
a. somatic
b. Hyploid
c. Egg
d. Centromere
A quick comparison
Mitosis
Meiosis
Repairs my body
½ mom+ ½ dad
Identical to mom cell
unique cell
Asexual
Sexual
Diploid 2n
Haploid shared chromosomes
I, P, M, A, T, C
Interphase, Phrophase, Metaphase,
Anaphase, Telophase, Cytkensis
I, P,M,A,T,C I & P,M,A,T II
Interphase I, Phrophase I, Metaphase I,
Anaphase I, Telophase I, CytkensisI &,
Phrophase II, Metaphase II, Anaphase II, Telophase II,
2 cells
4 cells
Heterogeneous
Homologous
Somatic (body cells)
Gamets (sex cells)
Congratulations you completed the tutorial on Mitosis and Meiosis