Mitosis And Meiosis Essay

Biology Mitosis Lab
AP BIOLOGY–
Mitosis and Meiosis Cell Division Lab
Part 1–MITOSIS
summary:
In this experiment first the stages of an onion cell undergoing mitosis are going to be observed and
every stage is going to be detected and drawn on paper. A brief description to what is going on
should be attached to the pictures. This is important to understand the basics of cell division which is
necessary growth,repair and asexual reproduction. Second the number of cells undergoing each
phase is going to be counted to figure out in which phase the cell remains the most. If interphase is
the stage in which the cell grows and prepares for cell division then the...show more content...
Later on a male and female haploid cell will join to form a diploid cell with the right number of
chromosomes.
Meiosis consists of one DNA replication and two nuclear divisions resulting in 4 daughter cells.
The process which provides for genetic variation is crossing over. Crossing over occurs in the early
stages when homologous chromosomes move together so that their chromatids form a tetrad. This is
called synapsis and allows for the exchange of chromosome sections.
In our case the crossing overs will result in different colorings of the ascospores of the S. fimicoli.
Materials:
–Microscope
–S.fimicola meiosis cards
Procedure:
1–Study the different phases of meiosis on the cards.
2–Notice the difference between ascospores with sequences of 4's and 2's.
3–Count the amount of different sequences present.
4–From the data you gathered calculate the percentage of asci showing crossover.
Analysis:
Out of a total from 26 sequences only 6 were made up of 4's while 20 were composed of different
structures of 2's. This tells us that 77% of the asci showed crossing over while 23% did not.
Conclusion:
Our hypothesis that if meiosis is present the new formed asci will have different colors was
supported by the outcome of our observations. The fact that different sequences of 2's emerged from
the first pattern of 4's is prove that crossing over took place.
Genetic

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Compare and Contrast Mitosis and Meiosis Essay
Compare and Contrast Mitosis and Meiosis
Meiosis and mitosis describes the process by which cells divide, either by asexual or sexual
reproduction to produce a new organism.
Meiosis is a form of cell division that produces gametes in humans these are egg cells and sperms,
each with reduced or halved number of chromosomes. The number of chromosomes is restored
when two gametes fuse together to form a zygote. A cell with two copies of each chromosome is
called diploid cell and a cell with one copy of each chromosome is called a haploid cell. Meioses
produces haploid daughter cells that are genetically different from each other and from the parent
cell. However, mitosis is a form of cell division that produces daughter cells...show more content...
These bivalents line up along the equator during metaphase I, the arrangement of the bivalent is
completely random and relative to the orientation of the other bivalents, this is known as the
independent assortment of chromosomes. This is followed by anaphase I where the homologous
chromosomes separate and move to the opposite poles of the cell.
At telophase I the cell divides into two, each cell contains one chromosome from each homologous
pair. The second stage of meiosis is similar to mitosis. These centrioles replicate and the
chromosomes line along the equator at metaphase II and spilt at the centromeres causing the
chromatids to move to opposite sides at anaphase II. At telophase II the cell divides to form four
haploid cells, these are not identical to each other because the cells contains chromosomes from two
different parent gametes therefore differ genetically.
However, during mitotic division the cells produced are genetically identical to each other because
they are produced from the same parent cell. The cell begins to replicate during interphase to
produce two identical sister chromatids. At prophase the chromosomes become condense to become
visible and the membrane begins to break down. The chromosomes line up along the centre of the
equator during metaphase.
The chromatids separate and are pulled to opposite poles during anaphase. In telophase these
separate chromatids

Meiosis Vs Mitosis
Life forms display an assortment of examples in respect to propagation, and diverse perspectives
might be brought with respect to arrangement of these patters. For our motivations, we might
consider that there are two essential sorts of multiplication, sexual and asexual. Sexual
reproduction is always associated with a type of nuclear division called meiosis which occurs at
some point in the life cycle of the organism involved. Besides, aside from a couple of atypical cases,
sexual multiplication is portrayed by the union of gametes, or particular conceptive cells, in the
development of another person. Such gametic union is trailed by the combination of the diversion
tic cores and the relationship of their chromosomes: this whole arrangement of occasions is known
as treatment.
Cells separate and replicate in two ways: mitosis and meiosis. Mitosis is a procedure of cell division
that...show more content...
Not just is mitosis in charge of abiogenetic propagation in single–celled life forms, however it is
likewise what empowers cell development and repair in multicellular living beings, for example,
people. In mitosis, a cell makes a precise clone of itself. This procedure is what is behind the
development of youngsters into grown–ups, the recuperating of cuts and wounds, and even the
regrowth of skin, appendages, and members in creatures like geckos and reptiles. Meiosis is a
more particular kind of cell division (of germ cells, specifically) that outcomes in gametes, either
eggs or sperm, that contain half of the chromosomes found in a guardian cell. Not at all like mitosis
with its numerous capacities, meiosis has a slender yet critical reason: helping sexual multiplication.
The procedure empowers youngsters to be connected yet at the same time not the same as their two
guardians. (Westbroek,

Mitosis And Meiosis
Mitosis Meiosis
Most of the times people get injuries, complex or simple one like bruises and, within a period of
time, these injuries heal. This healing process is made possible by cell division whereby a single
cell divides to form two and the process continues. The same process also helps living things grow,
for example, over 2 trillion cells divide every day in human beings. There are two types of cell
division processes; mitosis and meiosis, each of which has distinct characteristics.
Definition
Mitosis: A single cell divide into two genetically identical cells. This process is asexual in nature
and the two resulting cells have equal number of chromosomes in each of the diploid cells each with
identical nuclei.
Meiosis: Meiosis is a sexual cell reproduction process whereby a single cell divides its homologous
chromosomes equally to form two haploid cells with half the chromosomes of the parent cell.
Process
Mitosis: Mitosis occur in five phases describing the changes through which the cells go through.
These stages are prophase, prometaphase, metaphase, anaphase, and telophase. In prophase, the
chromosomes condense inside the nucleus while centrioles move to the opposite within the nucleus
sides in pairs. As this process...show more content...
The chromosomes then split into two sister chromatids which the centromeres hold together. This
therefore mean that there are two sets of sister chromatids (four chromatids) in the two
chromosomes. Two non–sister chromosomes cross over as the other two remain. Secondly, in
metaphase I, chromosomes line up at the center of the spindle fibers in pairs then the third phase,
Anaphase I begins when equal amounts of chromosomes divide. On the last phase, telophase I, the
daughter cells completely divide, chromosomes disappear, and the nucleic membranes

Mitosis Vs Meiosis Research Paper
Mitosis and meiosis are both types of cell divisions that have various similarities and differences.
They comparably associate with cytokinesis and form daughter cells however, meiosis occurs in
primordial diploid cells in animals, plants and fungi, whilst mitosis takes place in somatic cells in
every organism (Vidyasagar. A, 2015). Meiosis differs frommitosis as it undergoes a process known
as DNA recombination, during which genetic material interchange with chromosomes or various
regions of the same chromosome. DNA recombination is a common source of genetic variation.
Mitosis is the continuous process by which the body creates new cells to repair damaged or aging
membranes, fibers and tissues (Clare O'Connor, 2008). The end result of mitosis are two
genetically identical diploid daughter cells, which develop from the single parent cell dividing.
Conversely, the meiosis cell divides into four haploid gametes each possessing half the number of
chromosomes of the parent cell (Alberts. B, 2010).
Fertilisation occurs when the two female and male gametes fuse, causing a diploid cell...show more
content...
Moreover, since rice is the main staple and is eaten in enormous amounts in developing countries,
Golden Rice could eventually lead to excessive intake of vitamin A which is also known as
hypervitaminosis or vitamin A toxicity. This causes vomiting, abdominal pain, dizziness, central
nervous system disorders, increased risk of osteoporosis and incomplete formation of the cranial
bone of a fetus (Greenpeace, 2014). Score(–5) More than 250 million children worldwide suffer
from vitamin A deficiency in developing countries, over 500,000 people, mainly children, become
blind every year due to vitamin A deficiency and 50 percent of which die within a year of becoming
blind (Bjorn. L,

Mitosis: Interphase I And Meiosis
Mitosis and meiosis are the means by which reproduction takes place. Mitosis creates an exact
duplicate of cell so that old cells can be replaced, such as in skin, hair, and bones. Meiosis allows a
cell to unite one half of its genetic makeup with a cell from another partner to create an entirely new
organism.
Mitosis
Mitosis is the process by which two daughter cells are formed, each containing a complete set of
chromosomes. Mitosis is the process by which an organism creates new cells, such as skin or bone.
There are two parts to a cell's life В– interphase and mitosis. Interphase is the normal life of the cell
when all of the growth and metabolism processes take place. Mitosis happens after interphase is
complete and produces an...show more content...
Meiosis is broken into two parts called Meiosis I and Meiosis II.
Meiosis I
The stages of Meiosis I are called prophase I, metaphase I, anaphase I, and telophase I. Prophase I is
like prophase in mitosis. However, in metaphase I, instead of pulling the chromosomes away from
their duplicates, the microtubules attach so as to pull the like pairs, called homologues, apart and
leave the chromosomes attached to their duplicates.
In anaphase I, the microtubules of the spindles pull the homologues apart.
In telephase I, the plasma membrane pinches the cell into two parts and the chromosomes are
surrounded by nuclear material. At the end of meiosis I, two haploid cells have been created, but
they still have duplicated chromosomes, so the cell must enter meiosis II.
Meoisis II
The purpose of meiosis II is to create cells with no duplicates, for purposes of reproduction. In
meiosis II, there are now two cells going through the process. Prophase II and metaphase II occur
just as in mitosis, but remember, there are two cells now.
During Anaphase II, the microtubules pull the duplicate chromosomes away from the originals.
During Telophase II, the plasma constricts and nuclei are formed.
Meiosis 2 is similar to mitosis, however, at the end of meiosis II, four haploid cells called gametes
have been formed, each with no duplicate chromosomes. The chromatids of each chromosome are
not identical

Compare And Contrast Mitosis And Meiosis
Meiosis and Mitosis are very similar despite a few differences and they both lead to different
outcomes.
Mitosis is the nuclear division that produces two nuclei containing chromosomes identical to the
parental nucleus. Mitosis is divided into five stages; prophase, prometaphase, metaphase, anaphase,
and telophase.
Meiosis is a cell division that reduces chromosome numbers.
The significance of Meiosis is that by recombination and sexual reproduction the genetic diversity
helps natural selection.

Mitosis And Meiosis Similarities
Mitosis and Meiosis are two very important topics to learn about within school. It is easy to
confuse the two, because they sound so similar, are similar, but also very different. Mitosis occurs
when the human body grows and it is asexual because no sexual interaction needs to take place.
Meiosis occurs during sexual reproduction and the creation of DNA. There are many similarities and
differences between Mitosis and Meiosis. Daughter cells are formed when a cell is duplicated.
Mitosis contains two identical daughter cells. These are identical to the parent cells because they
have the same number of chromosomes. Meiosis has four unique daughter cells. They are unique
because they are not the exact same as the parent's cell. Within Mitosis,

Mitosis Vs Meiosis
Cell division is a process that is essential to the reproduction, survival, and improvement of many
eukaryotes. Many things about cell division are still unknown, and each day scientists begin to
understand more about why something they already knew happened, happened. Such as the
underlying reactions and thermodynamics that motivate something to do what it does without
intelligence (Khan Academy). There are two types of cell division under this category, and they are
mitosis and meiosis. Although they fall under the same category, they have similarities and
dissimilarities. To avoid confusion and for better understanding they will be discussed in pairs
(similar–dissimilar), and there may be some overlap in points as this is the nature of the subject
matter.
To begin, the most obvious differences and similarities will be addressed. Both processes follow
interphase which replicates the DNA. They both begin with a cell that has a diploid number of
chromosomes. Mitosis is a repeatable cycle, and meiosis is not. Mitosis proceeds to completion and
ends with cells that are capable of going through the cell cycle and repeating the process...show more
content...
Although they do occur in the same organism, they occur in different places. Mitosis is the
duplication of somatic, or body, cells. Meiosis is the duplication of germ, or sex, cells. Because
meiosis involves sex cells, the products are capable of fertilization. One difference mentioned
before but not much expanded upon is that meiosis gives cells that come from diploid cells but are
haploid. Because the information they receive is spilt between the two, each cell contains different
information selected at random. Mitosis in contrast is a process that yields two cells that are an
exact copy of their parent cell (excepting an occasional mutation). Each cell that results from mitosis
is identical to its parent and contains the same genetic

Essay about Lab 8, Mitosis and Meiosis
Julie Lake
November 8, 2012
BIO 111, C11– Online
Villalpando, Shawn
Lab 8
Title: Mitosis and Meiosis
Exercise 1: Mitosis in Animal and Plant Cells
Questions:
A.) What is the purpose of mitosis?
The purpose of mitosis is to create or produce more cells for a living organism. Mitosis occurs when
genetic substance in the nucleus divides or separates in order to create more cells. Cytokinesis
normally occurs next and the single cell develops into two separate cells. This same process
continues to occur over and over creating more cells for an organism replacing old or dead cells.
B.) What other term is commonly used in place of "mitosis"?
Another commonly used term for "mitosis" is "cell division", because the division of cells is...show
more content...
Observations:
Whitefish Blastula cells:
Onion Root Tip cells:
Exercise 2: Meiosis in Animals
Questions:
A. Which organ, the ovary or the testes, contained the greater number of gametes?
The organ that contained the greater number of gamets is the testes.
B. What may be a reason for this?
The eggs in the ovary are much larger than the sperm in the testes and it takes numerous sperm
trying to get to the egg before one actually does fertilize the egg and most of the sperm die trying.
Observations:
Ovary:
Testis:
Exercise 3: Simulating Meiosis
Questions:
A. What does mitosis accomplish?
The process of mitosis accomplishes replacing old or dying cells in an organism by replicating the
DNA and cell division.
B. When and where does mitosis occur?
Mitosis occurs in eukaryotic cells during the interphase of cell division.

C. What does meiosis accomplish? Meiosis has two consecutive cell divisions that produce a total of
four genetically different daughter cells.
D. When and where does meiosis occur?
Meiosis occurs in the ovaries and testes or reproduction organs during interphase.
E. How do these two processes differ?
Mitosis creates identical cells to replace old or dying cell tissue while Meiosis occurs in the sexual
reproduction organs and creates genetically different cells.
F. How do Prophase in Mitosis and Prophase I in Meiosis differ?
In mitosis chromosomes create two sister

Comparing Mitosis and Meiosis Essay
Comparing Mitosis and Meiosis with reference to i. Chromosomesii.
Biological significance
i. Chromosomes ii. Biological significance
Modern cell theory states that all cells are derived from other cells.
This means cells must have a way of copying themselves. This is cell division; two types of cell
division are Meiosis and Mitosis. The comparison will be between Meiosis 1 and Mitosis, because
Meiosis 2 is much the same as Mitosis.
Dividing cells have a regular pattern of events, known as the cell cycle. This cycle may be divided
into two basic parts; The Interphase and the actual division (Meiosis / Mitosis).
Interphase is when the cell is not dividing but duplicating its DNA and organelles. Both Meiosis 1
and...show more content...
At this point the chromatids may break and recombine with different chromatids, this is called
crossing over.
Metaphase
In Mitosis Metaphase stage the chromosomes go to the centre/equator of the spindle. The
chromosomes get attached to spindle fibres at the centromere, when these contract; the individual
chromatids get pulled apart slightly.
In Meiosis Metaphase 1 is similar to Mitosis stage one but differs as chromosomes form a double
row at the equator of the spindle instead of a single row.
Anaphase
In Mitosis and Meiosis Anaphase; the centromere splits as a result the spindle contract further and
the two chromatids of each chromosome separate and migrate to opposite ends. The spindle fibres are
made of tubulin molecules and they shorten through the removal process. The energy for this
process is provided by mitochondria, which surround the spindle fibres.
Telophase
In Mitosis and Meiosis Telophase the chromatids reach their respective poles and a new nuclear
envelope forms around each group. The chromatids uncoil and lengthen, becoming invisible again.
The spindle fibres disappear and a nucleolus forms in each new nucleus.

Comparing Mitosis and Meiosis with reference to Chromosomes
Mitosis
Meiosis
A single division of the chromosomes and the nucleus
A single division of the chromosomes but a double division of the nucleus The number of
chromosomes remains the same
The number of

Essay on Meiosis Vs. Mitosis
More than one celled organisms grow by way of mitosis and the cytoplasmic division of body
cells. On the other hand, meiosis occurs only in germ cells, which are put aside for the formation of
gametes (sperm and egg). Reproduction by meiosis allows for species survival and it increases
genetic variability.
The process, during which the germ cells are generated is called meiosis. It represents nature's
solution to the problem of chromosome doubling that would occur, if two diploid cells, i.e. two
cells with a double set of chromosomes would fuse. Accordingly does meiosis produce haploid germ
cells, with maternal and paternal germ cell fusing at fertilization and thus generating a...show more
content...
Chromosome pairs line up across the equator of the spindle at metaphase I (5). In anaphase I the
chromosomes separate and travel to opposite ends of the spindle. The chromosomes migrate to the
equators of two new spindles for metaphase 2 (7). Next the chromatids are pulled apart in anaphase
2 to form four clusters of chromosomes in telophase 2. The nuclear envelopes reform around four
haploid nuclei that will give rise gamete
The leptotene. This phase differs only slightly from the early stages of mitosis. Usually are the cells
and nuclei of meiotic tissues bigger than that of their neighbouring tissues and often do they seem to
be longer and are longitudinally structured. At regular intervals can thickenings be found, like beads
on a string: the chromomeres. Their number, size and positioning is constant in each species.
The zygotene. During this phase begins the pairing of homologous chromosomes. It is also called
synapsis and the resulting structure synaptic complex. Directly after initiation of the process does
the pairing spread like a zipper across the whole length of the chromosome.
The pachytene. During the pachytene does the pairing stabilize. The number of synaptic complexes
corresponds to the number of chromosomes in a haploid set of the respective species. The pairs are
also called bivalents. The

The Process of Mitosis Essay
The Process of Mitosis
Mitosis is the term used to describe cell division for replication. The product at the end of mitosis is
two daughter cells both genetically identical to the original (parent) cell. This process (mitosis) is
used for growth and repair within an organism (and also for asexual reproduction).
There are five main stages to mitosis, called Interphase, Prophase, Metaphase,
Anaphase and Telophase. Although the process has been divided up into these stages the process of
mitosis is actually continuous.
Interphase ––––––––––––––––––––––––––––––––––––––– In this, the first stage the cell will look
just like any other 'normal' cell although this is far from the case because very much is actually
happening. All cell...show more content...
[A labelled diagram of the end of the Prophase stage of a cell here would be great.] Metaphase
––––––––––––––––––––––––––––––––––––––– During this stage the chromosomes move towards
the equator of the spindle, attaching themselves horizontally by the centromere to the spindle's
filaments. The chromatids then pull slightly away from each other at the centromere towards the
opposite poles of the cell.
[A labelled diagram of Metaphase here, and put a note next to it saying "Note that some
spindle fibres run from pole to pole while others from pole to equator."] Anaphase
––––––––––––––––––––––––––––––––––––––– Now this stage is very quick.
The pairs of chromatids are separated and each chromatids is pulled is pulled towards each opposite
pole by the spindle fibres by a ratchet–like mechanism.
This process requires energy so the ATP store is now used up.
[A labelled diagram of Anaphase. Write a note underneath saying "They split apart by the
centromere breaking into two. Each centromere divides into two so that each chromatid has its own
centromere."]
Telophase ––––––––––––––––––––––––––––––––––––––– The chromatids are destined to become
the new chromosomes of the daughter cells. Once the chromatids are at the poles of the cell they
unwind into chromatin again, now becoming hard to see once again. The spindle fibres now
disintegrate and new nuclear membranes form around the new groups of chromatin

Cell Biology Meiosis and Mitosis
Cell Biology (CP8121)
Experiment 2: Observing Mitosis and Meiosis on cell specimens
(Formal report)
Name: Wong Chung An
Class: DMLS/FT/1B/02
Admin number: P1138687
Summary
This experiment aims to observe mitosis and meiosis on cell specimens. It involves the modelling of
the stages of meiosis and also the staining procedures to identify mitosis in onion root tip. There are
two parts to the procedure of the experiment whereby the first is staining and observing mitosis in
onion root tips and the second being observing and comparing mitosis between whitefish blastula
and onion root tip. The results are that the five stages of mitosis have been observed and sketched,
together with a comparison of telophase in plant and animal cells. The...show more content...
2) This time, instead of sketching the different phases of mitosis in onion root tip, the differences in
mitosis between the plant and animal cells were recorded.
4) Results and Discussion
*For the results, refer to the datasheet archived under appendix at the end of the report.
5.1 Explanation and reasons for results
The results of the datasheet have shown that all the five main phases of mitosis can be observed.
This can because of several reasons such as the choice of use of onion root tips, flattening of the
onion root tips, addition of hydrochloric acid and 0.5% Toluidine Blue solution.
Onion root tips are easy to grow in large numbers and the cells at its tips are actively dividing, thus
many of its cells will be in different stages of mitosis. The reason for using the last 1–3mm of the
root tip is because it is where the region of cell division (meristem) is located. This is the region
whereby cells are dividing but not significantly increasing in size.
The flattening of the onion root tips allows the chromosomes of each individual cell to be
observed. The hydrochloric acid added, plays a part in fragmenting the root tissues by weakening
and removing the bonds between cells so that each cell will not be attached to the other cell,
obstructing the observation. Toluidine Blue solution acts as a colorant, giving a blue colour to the
chromosomes and so that it is more easily spotted

Mitosis and Meiosis
Cell division may happen by either mitosis or meiosis, depending on what type of cell is
invovled. Mitosis is a process by which a cell divides to form two daughter cells. They each have
the same exact number and kind of chromosomes as the parent cell. Meiosis occurs in the primary
sex cells leading to the formation of viable egg and sperm cells. They reduce the number of
chromosomes to half in each gamete so that when they are getting furtilized, the species chromosome
number is kept even.
Mitosis happens in the reproduction of unicellular organisms and in the addition of cells to a tissue
or organ in a multicellular organism.
There are four stages of mitosis. The first stage is the prophase. In this stage the chromosomes
become...show more content...
There are two major ways of reproduction, asexual and sexual.
Asexual reproduction only involves one parent. They split their cell in half. Sexual reproduction
involves two parents and they each have one cell (either an egg of sperm) which gets put together to
have an infant. The egg and sperm usually have 23 chromosomes. SO when an infant is born, it has
46 chromosomes.
A con for sexual reproduction is during meiosis. An egg and sperm cell usually have 23
chromosomes each. When an egg gets fertilized by a sperm cell it combines to 46 chromosomes.
Human beings have 46 chromosomes each. When something goes wrong and a baby inside a womb
gets one more extra chromosome, they get Down syndrome.
A pro for sexual reproduction is that two parents can have the joy of having their own child. Some
people grow up and end up not being able to carry out a child because of some defect in their body.
A con for asexual reproduction is that bacteria multiply by asexual reproduction. If you have a
sickness and you don 't realize it in time, the bacteria can spread all over your body until you get
extremely sick.
A pro for asexual reproduction is that flowers, trees, and other plants multiply by asexual
reproduction. The environment is being destroyed and with flower, tree, and plant seeds, people
will be able to grow these things that are being destroyed. They can also rebuild habitats for animals
that are also being

Difference Between Mitosis And Meiosis
They are made of nuclear DNA and proteins.
Mitosis and meiosis are related to each other through the process of cytokinesis. In addition, these
processes are the same in terms of sequence in the steps of cell division, however meiosis role the
process twice. The outcome of them are similar, because they both done with daughter cells.
Cancer is caused by the mutations of genes within the somatic cells. This disease develops in the
somatic cells during the process of cell division because of mutations. A few faults in the copying
process transpire when the DNA is replicated prior to cell division. Another factor that can cause
rapidly dividing cells is by chemicals and radiation that causes damaging DNA. With this knowledge,
I have invented the...show more content...
I estimated that all stage of the cell cycle would have the same time. The data shows that most of
the cells were located in the initial stage of mitosis, Interphase.
By the end of the first meiosis, each separate individual cell has its set of homologous pairs of
chromosomes. While at the last stage of meiosis II, all of the haploid cells have their own sister
chromatid from the homologous pairs.
DNA is the set of instructions for all organelle and its' function. Chromosomes are important, because
they carry the DNA.
The first phase of meiosis is mostly about splitting the cells in half and the separation of homologous
chromosomes. In contrast, the second phase of meiosis focuses on the separation of chromatids
along with the 2 diploid splitting in 2.
There were 46 chromosomes present when the first meiosis began.
The gamete cells result in the combination of two cells from both genders to build one new zygote,
because of that, it is important to reduce the number of chromosomes in gametes. On the other hand,
other cells contain a unicellular reproduction and that shows that no need to reduce the amount of
chromosomes.
There is no male gamete.
There are 57 chromatids.
The paired chromosomes contain varied lengths.
The sixth doesn't has

Meiosis Research Paper
Every cell on Earth has certain things in common; such as a plasma membrane, the presence of
DNA and the ability to respond to stimuli, as well as reproduce. Some things such as viruses can
seem to be living; however, the lack the ability to reproduce by themselves and instead they tack
advantage of the amazing ability of most cells to produce macromolecules and to produce daughter
cells from a parent cell. Just like every human being is born, undergoes a period of growth and
eventually dies; so does each individual cell that composes that human being. In addition, just as
human beings undergo a period of maturation that if they pass a certain level of physical maturity,
they may reproduce; so do the cells that compose said human being. In...show more content...
The end goal of meiosis includes twice as many daughter cells as mitosis; therefore, there is a
second cell division involve similar stages. Interphase is different in meiosis than in mitosis
because each individual homologue is replicated instead of replicating one chromosome. Mitosis
involves the replication of somatic cells that are haploid; whereas, meiosis involves the
manufacturing of gametes that are genetically haploid. In prophase I paired homologues are
attracted to one another at the synapsis and a process called crossing over takes place. Crossing
over involves a genetic rearrangement of DNA of the same segments. Otherwise prophase 1 is
similar to prophase in mitosis. In metaphase I chromosomes line up in homologous pairs,
otherwise this stage is similar to metaphase in mitosis. Anaphase I, Telophase I, and cytokinesis is
the same in meiosis as in mitosis except, two haploid cells form with each chromosome still
consisting of two sister chromatids. The second stage of meiosis involves all the same steps except
there is no crossing over involves because each cell is now genetically haploid. The set of sister
chromatids undergoes prophase II, metaphase II, anaphase II, telophase II, and cytokinesis. The
sister chromatids finally separate resulting in four haploid daughter cells containing unduplicated
chromosomes. In prophase I crossing over took place, and this results in each chromosome being
genetically different in each of the four daughter

Mitosis and Meiosis
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Cell division
The human body is made up of trillions of cells...
Mitosis and Meiosis
...But started with one
Understanding Cell Division
What instructions are necessary for inheritance? How are those instructions duplicated for
distribution into daughter cells? By what mechanisms are instructions parceled out to daughter cells?
Reproduction
Parental cells produce a new generation of cells or multicelled individuals like themselves Parents
must provide daughter cells with hereditary instructions, encoded in DNA, and enough metabolic
machinery to start up their own operation
The roles of mitosis
Chromosome
A DNA molecule & attached proteins Duplicated in preparation for mitosis
1...show more content...
Meiosis is the process that produces haploid gametes from diploid genomes.
Maintaining Chromosome Number In Mitosis
Meiosis must reduce chromosome number
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Chromosome Number
Sum total of chromosomes in a cell Germ cells are diploid (2n) Gametes are haploid (n) Meiosis
halves chromosome number When two gametes fuse, they form a new, diploid cell (zygote)
Human Karyotype
Diploid organisms have two copies of each chromosome, one of which they get from their father, the

other which they get from their mother. These equivalent chromosomes are called homologous
chromosomes.
Life Cycles of Diploid Organisms
Meiosis: Two Divisions
Two consecutive nuclear divisions
– Meiosis I – Meiosis II
DNA is not duplicated between divisions Four haploid nuclei form
Meiosis has two divisions
Do not confuse "homologous" with "sister" chromosomes
Sisters Sisters Homologs
Sisters
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Meiosis – Stages
Prophase I
Each duplicated chromosome pairs with homologue Homologues swap segments (crossing over)
Each chromosome becomes attached to spindle
Metaphase I
Homologous pairs line up in the middle of the cell The spindle is fully formed
Anaphase I
Homologous chromosomes segregate The sister chromatids remain attached
Telophase I
The homologous chromosomes arrive at opposite poles Usually followed by cytoplasmic division
Results of Meiosis I

Essay Mitosis and Meiosis
Cell division may happen by either mitosis or meiosis, depending on what type of cell is
invovled. Mitosis is a process by which a cell divides to form two daughter cells. They each have
the same exact number and kind of chromosomes as the parent cell. Meiosis occurs in the primary
sex cells leading to the formation of viable egg and sperm cells. They reduce the number of
chromosomes to half in each gamete so that when they are getting furtilized, the species chromosome
number is kept even.
Mitosis happens in the reproduction of unicellular organisms and in the addition of cells to a tissue or
organ in a multicellular organism.
There are four stages of mitosis. The first stage is the prophase. In this stage the chromosomes
become shorter...show more content...
The spindle fibers extending from the poles to the centromeres disappear and those fibers that lie in
the plane between the rows of chromosomes remain for a longer time. A nuclear membrane reforms
around each bundle of chromosomes at the poles. At the center of animal cells, the cytoplasm turns
inward, pinching the old cell into two new cells.
Meiosis happens in the primary sex cells, which leads to the formation of viable egg and sperm
cells. The purpose of meiosis is to cut the number of chromosomes in half.
There are two stages of meiosis, meiosis I and II. Meiosis I has five stages called prophase I,
metaphse I, anaphase I, telophase I, and interkinesis I. Meiosis II has only four stages. They are
prophase II, metaphase II, anaphase II, and telophase II.
The stages of meiosis I result in the reduction of the number of chromosomes.
In prophase I the chromosomes become shorter and thicker and the nucleolus disappears. The
chromosomes pair with their homologues forming a group of four chromatids. The tetrads wrap
around each other and may exchange like parts. The centrioles move and the spindle fibers appear
and the nuclear membrane disappears.
The tetrads move as a group to the equator in metaphase I. The centromeres of each of the
homologous pairs of chromosomes become attached to spindle fibers extending from opposite poles.
Each pair of double–stranded chromosomes, in anaphaseI, is pulled away from its homologue

Lab Report On Mitosis And Meiosis
MITOSIS
by Alimzhan Muxunov
Group M
16.10.2014
Lab partner: Gulzhan Belgibay
INTRODUCTION One of the vital processes, which are very important for cells' life, is called cell
division. There are two types of it called mitosis and meiosis. In this practical, we will focus on
mitosis. Mitosis is a part of eukaryotic cell division cycle, when a nucleus divides into two new
nuclei. Prokaryotic cell does not have nucleus, so mitosis does not occur there. According to Kent
(2000) and Campbell (2009), mitosis consisted of four steps: Prophase, Metaphase, Anaphase and
Telophase. Interphase is the preparation of cell to mitosis: growth of the cell and its' organelles,
replication of DNA occur during this period. Mitosis starts with prophase, when the chromosomes
are coiled and become shorter, next stage is metaphase when chromosomes line...show more
content...
Interphase is a preparation of the cell to mitosis, during interphase DNA duplicates, but
chromosomes actually are not visible on this stage. Interphase requires for minimum 90% of the
whole time of cell division (Campbell 2009, p.129). The first step of mitosis is a prophase, when
chromosomes become more visible, nuclear membrane disappears, mitotic spindle forms in the
cytoplasm and centrioles move to opposite sides of the cell (Kent 2000, p. 76). The next stage
after this is metaphase, during which chromosomes line up at the equator of the cell, after that
process spindle fibers attach to chromosomes from two opposite sides (Kent 2000, p. 76). The
stage of separating paired chromosomes and their movement to the opposite poles of the cell is
called anaphase (Kent 2000, p. 77).The last step of mitosis is telophase, during which new
membranes of two daughter nuclei appear and chromosomes become less visible(Kent 2000, p. 76).
Mitotic index, which is used when the growth of tumour in cancer patients is studied, was

Mitosis And Meiosis Essay

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