Mitosis Ana Djurica

Mitosis is cell division in the cell cycle, that ends with producing two identical cells-daughter cells. The 1st stage of cell division is interphase. Interphase is the phase of the cell cycle in which a typical cell spends most of it's life, the 'daily living' or metabolic phase of the cell, in which the cell obtains nutrients and metabolizes them, grows, reads it's DNA, and conducts other "normal" cell functions... It is divided into 3 phases; G1(gap phase 1), S(synthesis) and G2(gap phase 2). 

The ilustration of interphase

• G1-cell grows larger

• S-genome is replicated

• G2-separates the newly replicated genome and marks the end of interphase.

The cell cycle

Mitosis-events that occur in 4 phases of it:

1. Prophase-the spindle microtubules grow and extend from each pole to the equator, chromosomes super coil and become short and bulky and the nuclear envelope breaks down.
2. Metaphase-the chromatids move to the equator and the spindle microtubules from each pole attach to each centromere on opposite sides.
3. Anaphase-the spindle microtubules pull the sister chromatids apart splitting the centromeres. This splits the sister chromatids into chromosomes. Each identical chromosome is pulled to opposite poles.
4. Telophase-the spindle microtubules break down and the chromosomes uncoil and so are no longer individually visible. Also the nuclear membrane reforms. The cell then divides by cytokinesis to form two daughter cells with identical genetic nuclei.

Interphase+4 phases of mitosis

Sources:

•  http://ibguides.com/biology/notes/cell-division
• https://en.wikipedia.org/wiki/Interphase

MITOSIS

Mitosis is the  a process of cell division in which two new nuclei are formed, each containing the original number of chromosomes. The two newly formed nuclei are known as identical daughter cells. When mitosis occurs the chromosomes from one nucleus split into two matching sets which inhabit each daughter cell. The duplication and split of the chromosomes occurs in order for the twin daughter cells to be able to obtain information for future functions.

Figure 1:
The S stage

In order for this process to occur, each cell must undergo a repeating set of events, which occur in the beginning stages of the cell cycle also known as the interphase. The replication of genetically identical nuclei is reached through the four phases of mitosis; prophase, metaphase, anaphase and telophase. The first stage, the interphase can be further broken down into 3 stages/phases. The G1 stage, the S stage and the G2 stage. However the duplication of the DNA only occurs in the S stage. During the S phase, the DNA replicates resulting in the production of 2 copies of each chromosome, as shown in Figure 1. The cell then moves onto phase G2, where it continues to prepare for mitosis and cell division.

Mitosis, as mentioned above is a process composed of 4 stages, the first stage being prophase. During prophase the chromosomes, begin to condense or in other words thicken. The twin copies of each chromosome are called the sister chromatids. The nuclear membrane which surrounds and protects the cell nucleus disintegrates (breaks apart into pieces), the nucleolus then disappears, and the centrosomes move towards opposite poles of the cell. During the movement of the centrosomes the spindle fibers, which grow out of the centrioles, form and move to opposite poles of the cells as well. Metaphase is the second stage of mitosis. During this stage the duplicated chromosomes line up in the center of the cell. The spindle fibers are now fully grown and formed allowing them to attach itself to each sister chromatids. The third phase, anaphase occurs when the sister chromatids of each chromosome begin to divide. The centromeres which have moved to opposite poles of the cell, and hold the sister chromatids together, split resulting in the chromosomes moving away from each other along the attached spindle fibers. The last phase, telophase is the phase in which the two groups of chromosomes reach opposite ends of the cell. The nuclear membrane as well as the nucleus begin to form around each group while the spindle fibers detach themselves from the chromosomes.

Post the process of mitosis, the last and final stage of the cycle occurs. This stage is called the cytokinesis and it is the stage in which the cell along with the cytoplasm split and divide into two identical daughter cells. Each daughter cell is made up of its nucleus which is a replica of the genetic material from the ‘’parent cell’’.

Figure 2
Visual representation of the stages of mitosis 

Mitosis KKesic

How does mitosis produce two genetically identical nuclei?


Mitosis is a type of cell division that in the end produces two daughter cells, with each having the same kind and same number of chromosomes as the parent nucleus.
 Two daughter cells -  occurs when a cell undergoes the cell cycle. The cell cycle has a couple of phases.The first being the interphase; which, as well,  has a couple of stages. The first stage is when the cell grows and matures. The second is when the DNA is copied. The third is when the cell is prepared for division, at this phase the two daughter cells still are not format because their process starts in the mitosis phase but in that phase they are still not developed but the nucleus divides into 2 identical nuclei and from that point in the next phase the two daughter cells are formed.. Mitosis is where the devision of diploid eukaryotic nucleus. The development of the two daughter cells is completed in the cytokinesis phase where the division of the cytoplasm occurs to from two daughter cells.

Figure 1: Cell cycle - from mitosis to two daughter cells which each contain the exact copies of the parent cell's chromosomes.
(Google Images) 

Mitosis is divided intro four stages:

• Prophase - the spindle microtubules grow and extend from each other to the equator from each pole. As they become short an bulky the nuclear envelope breaks down.
• Metaphase - chromatids move to the equator and the spindle microtubules from each pole attach to each centromere on opposite sides.
• Anaphase - the spindle microtubules pull the sister chromatids apart ,which splits the centromeres. This splits the sister chromatids into identical chromosomes. As they are then pulled to opposite poles.
• Telophase - the spindle microtubules break down. The chromosomes unhelix and they are not individually visible. The nuclear membrane reforms. Then, the cell divides to from two daughter cells with identical genetic nuclei. 

During the prophase, the chromosomes become more visible under a light microscope as they superhelix and become shorter and more ponderous. Then, the nuclear envelope fractures. Afterwards, the spindle microtubules grow and extend from each pole to the equator. So, at the metaphase the chromatids move to the equator. The sister chromatids are are two DNA molecules, that are formed by DNA replication; that is also how they are identical. In the anaphase, these sister chromatids are separated. While the spindle microtubules attaches to centromere and pulls the chromatids to opposite poles. The chromosome then occurs - while the sister chromatids are separated they are called chromosomes. Which would mean that each pole has the same chromosomes ( it is the same genetic material). The final step is when the microtubules break down. While the chromosomes unhelix and the nuclear membrane reforms. Then the cell divides into two daughter cells with each having genetically identical nuclei.

Figure 2: How a chromosome looks when duplicated
(Google images)

In further detail, during the DNA replication each chromosome produces an identical of itself; but at this point they are called chromatids and they are attached at the centromere. Then, the chromatids separate at mitosis and from the two identical daughter nuclei.

Figure3: Two daughter cells - showing how they are exactly the same and have the identical nuclei.
(Google images)

Resources:

"IB Biology HL Exam Study." - LiveBinder. N.p., n.d. Web. 11 Nov. 2015.

"The Cell Cycle, Mitosis and Meiosis." — University of Leicester. N.p., n.d. Web. 11 Nov. 2015.

Allott, Andrew, and David Mindorff. IB Biology. Oxford: Oxford UP, 2014. Print. IB Diploma Program - Biology Course Companion.

"

Benjamin Maglajac

Stem Cells

What is a stem cell?

A stem cell is an undifferentiated or only partially differentiated cell that is not yet associated with a determined function in an organism. A stem cell can either renew itself and produce identic cells through cell division or differentiate into further specialized cells. Depending on their ability to further differentiate, stem cells can be classified in totipotent, pluripotent or multipotent stem cells (Fig. 1). (National Institutes of Health)

Totipotent stem cells have the ability/potential to develop into an independent organism. They can only be found at the beginning of embryonal development (embryonic stem cells). 

Pluripotent stem cells have the ability/potential to give rise to any type of cell. However, they cannot develop into an independent organism. Pluripotent cells can be both, embryonic or adult stem cells.

Multipotent stem cells have the ability/potential to give rise different types of cells of a certain tissue.

(bag.ch)

Fig. 1: stages of differentiation/potency (stemcellclinic.com)

Obtaining stem cells

As we learned before, there are different levels of potency that a stem cell can have. Also, there are different methods for the exploitation of stem cells. The stem cells potency, discussed above (what is a stem cell) also depends on the source of exploitation.

Following I will focus on three basic methods and point out the specific advantages and disadvantages of each method.

Obtaining embryonic stem cells: embryonic stem cells, as their name suggests, are pluripotent stem cells that can only be obtained from a fertilized egg. After a few divisions when the fertilized egg reaches the stage of a blastocyst after a few divisions, the inner cells of the blastocyst are taken away which kills the fertilized egg. The cells gained by this procedure have an almost unlimited growth potential as well as the ability to differentiate into any type of specialized cell. However used for transplantation embryonic stem cells have a higher risk of becoming tumor cells than adult stem cells and rejection problems may occur.

Obtaining stem cells from the umbilical cord of a new born baby: hereby stem cells are gained from the blood extracted from the umbilical cord after it has been discarded as a process after every birth. Other than the embryonic stem cells this type of stem cells only has a limited potential for differentiation (multipotency, mainly blood cells). Great advantages of this method are that cord blood stem cells are easily obtained and stored and that there is a very low risk of rejection when used for therapy. However cord blood stem cells can only be obtained in small quantities.

Obtaining adult stem cells from deep tissues like bone marrow or fat tissue includes a more complex process of transplantation. As well as core blood stem cells adult stem cells have a limited growth potential and lower differentiation potential. Advantages of that method are the low risk of a tumor development and the compatibility of adult stem cells (Fig.2)

Fig. 2: Location of adult stem cells in the human body (learn.genetics.utah.edu)

(our biology book)

Stem cell therapy for Leukemia

The most commonly use of stem cells for therapeutic measures occurs in the treatment of leukemia. Leukemia is a type of cancer where cancerous blood cells, formed by mutation, appear to crowd out healthy blood cells in the bone marrow. The most commonly occurring type of leukemia leads to an overproduction of white blood cells, the so called lymphoblasts. This overproduction if not therapeutically treated leads to death in most cases. In order to heal a patient with leukemia first all the cancerous blood cells in the bone marrow must be killed which is being done by chemotherapy, the treatment with cell-killing chemicals. After that a transplant of healthy adult stem cells from a donor are put into the bone marrow where, after successful establishment, they again start producing blood cells.

(cancer.gov)

Ethical aspects of the stem cell therapy

The research and on the usage of stem cells for therapeutic means is one of the most controversial topics in medicine. Especially the usage of embryonic stem cells for research and therapy brings up a lot of ethical concerns. Is it ethical to artificially create and destroy life just in order to gain the highly potential stem cells of an embryo? Along this question, the next question that arises is when does an organism start to be “alive”? On the other hand did the usage of stem cells already reduced a lot of suffer and saved many lifes. But then again I personally ask myself if it is even good to keep on doing research in order to save so many lives? Isn’t our planet already overpopulated? And at what point does research has to stop? Soon we might be able to perform actual human cloning or grow our steaks on a dish just by using stem cells. But how are those desirable achievements? All these are neither yes- nor no- questions. In my opinion there is no right or wrong but we will certainly have to question our values and probably restate our perception of the value of life.

Stem Cells: Ajda

What are stem cells? 
According to Dictionary.com, a stem cell is, "an undifferentiated cell of a multi cellular organism which is capable of giving rise to indefinitely more cells of the same type, and from which certain other kinds of cell arise by differentiation." To simplify, Astem cells are a basic group of identical cells which have the ability to develop into any type of cell in the human body. Stem cells are the building blocks of our body. The ability to develop into any type of cell in our body is called specialization and every stem cell goes through this process. HowStuffWorks, explains that the embryo is where the very first stem cell is 'born'. The stem cells would then begin to reproduce and eventually develop the tissues, organs and other types of cells in the fetus's body.

Figure 1: Visual representation of all of stem cell's
possibilities of specialization. 

It is also important to note that a stem cell is pluripotent. This means that upon diving a stem cell is able to specialize into any of the 220 different cells in our body. 

Embryonic Stem Cells 

Embryonic stem cells are obtained from a human embryo, whose age ranges from four-five days and is in the very beginning phase of development called blastocyst. The creation of an embryo is the result of reproduction, where the men’s sperm fertilizes the female’s egg, first creating a zygote. A zygote is a single cell which when created begins dividing. Upon division the now created cells are called a blastocyst. The blastocyst is made up of an inner mass cell and an outer mass cell also known as the embryoblast and trophoblast. The embryoblast or the inner mass cell becomes a group of cells which will develop and specialize in order to become the various structures in an adult organism, while the outer mass cells or the trophoblast develops into a placenta. This then becomes the source of embryonic stem cells, which are then capable of developing/ specializing into any of the 220 different cells in our body.  

Adult Stem Cells 

Figure 2: The adult stem cells in their particular tissues

Adult stem cells are cells which are located in specific tissues all over our body. They ‘specialize’ in specific parts of their tissues. These cells have the ability to self-renew (basically means that they are able to divide/reproduce themselves over and over) which ensures that there is always a supply of cells ready to further specialize into specific cell types, when needed. Scientists have found these stem cells in several tissues from bone marrow, to the brain, the reproductive systems of both genders, skin, teeth etc. Adult stem cells are multipotent which means they are able to specialize into several kinds of cells within their tissues. However it is key to know adult stem cells do not generate cell types for other tissues. (Liver stem cells do not generate brain cells for example) 

Therapeutic Potential of Stem Cells 

For several decades now stem cells have been used to aid when curing certain types of cancer. Scientists have found that when patients undergo chemotherapy stem cells are destroyed which resulted in them removing these cells and then rejecting patients after their chemotherapy. They found that when doing so the stem cells produce a large amount of red and white blood cells which help fight infection and keep the body healthy. When scientists began to discover this, the cells were being removed and then reinjected from the bone-marrow, however since the late 1930’s they have been removed and then reinjected through the blood instead. Although the amount of ‘Peripheral blood cells’ (the cellular components of blood) is usually scarce, the amount can be increased with the use of particular drugs. This too, occurs post chemotherapy to ensure the survival of the stem cells. 

Ethical Issues of Stem Cell Therapy 

There are 3 main ethical issues raised when scientists bring up stem cell therapy.

1. Respect for human life: this has to do with showing respect for the human embryos. Embryonic stem cell research is believed to be unethical and inhumane as the embryo is destroyed during the process of stem cell line derivation. Many go as far as to accuse scientists of murder when conducting experiments with embryonic stem cells. One other major concern when dealing with respect for human life is the topic of cloning. The creation of embryos for the purpose of research, otherwise known as cloning may lead to ‘de-sensitization’ of the human life.

Figure 3: Process of cloning an embryonic cell

2. Human dignity: this concept is very unclear as it has no true meaning. Most people take human dignity as our essential humanity or what makes us human. This concept is again directly related to the human embryo.

3.  Status of the human embryo: many consider the human embryo to have the same moral status as a human being thus believing that the destruction and/or cloning of an embryo is to be considered murder. However, many also believe that through the later stages of development the moral value is gained. When expanded upon this means that it is in the belief of some that an embryo is not a living human yet and only gains moral status when it begins to expand and develop. 

For any further interest in the ongoing debates concerning ethical issues of stem cell therapy click here. 

If you wish to see a quick overview of the stem cells, and it's therapeutic potentials view this video. 

What are stem cells?

 What are stem cells?

Figure 1- Development of an Adult stem.

According to Stem Cells Australia the human body contains more that 200 different kinds of specialized cells, including the muscle cells, nerve cells, fat cells and skin cells. Stem cells are resembling cells that can be divided to produce offspring cells. Specialized cells originate from stem cells, and are different from normal cells in two different ways. Stem cells are capable of renewing and making copies of them selves, as well as dividing cells to produce more specific cell types such as tissues and organs. (Tissue cells can repair and replace infected cells in the body). Stem cells include the essential part of human development as they repair injuries (scars, broken bones,etc) and are included of our ageing process. 

Figure 1- Shows the possible development into specialized cells.

Different Stem Cells

Embryonic stem cells are formed when an female egg cell and sperm cell fuse, the process after continues as the zygote divides into a two cells ‘embryo’ and so on. Embryonic stem cells give rise to every cell type (all tissues and organs) in the fully matured body apart from the placenta and umbilical cord. According to Embryonic stem cells are very valuable because they provide  renewable resource for studying normal development and disease, as well as testing drugs and other therapies. 

Adult stem cells also known as tissue specific stem cells, are found specifically in the tissue or organ. The job of a stem cells is to replace cells from that tissue that are lost during the day or when injures, such as those in your skin, blood, and the lining of your gut.

Pluripotent cells have the ability to make cells in our body layers and produce any cell or tissue the body needs to repair itself. Pluripotent cells are able to remake/create more copies of themselves. 

(http://www.closerlookatstemcells.org/learn-about-stem-cells/types-of-stem-cells)

Therapeutic Potential of stem cells

Figure 3- Shows the influence of stem cells to the human body.
http://www.efpia.eu/topics/innovation/stem-cells

From the information above we found out that; all stem cells in our body have a specific function and are known to control our body's health. For example embryonic stem cells developed into cells from the organ it protects and adult cells grow to become different cells. On the positive side both adult and embryonic stem cells repel diseases. Coming to a conclusion, adult stem cells are more effective in controlling what goes on in the body's health as they are known to develop into different cells and will be more reliable to repel diseases. 

Ethical Issue of Stem Cell Therapy 

Figure 3- Portraying the message about the ethical issues.

With the recent discovery of lowering the risks of many diseases there are unfortunately ethical issues. During my research I have come across many cites mentioning the different embryo stem cell therapies. Embryo is formed from a sperm cell and an egg cell, as mentioned above. Embryo stem cells are the primary steps to the development of an organism. Discussions made around the world include the following;  People are acting as if they are god, as they create life by them self. The most popular ethical issue discussed is that stem cell therapy is considered to be “murder”, “value of a human life”  Although on the other hand the people who argue against this topic, claim that embryos are just cells clumped together and can't be considered to be life as "early pre-implantation stage embryos do not have the psychological, physiological, emotional or intellectualproperties that we associate with personhood". The view towards this ethical issue depends on the different religions. The majority believe that a human embryo has a right to live its own life, if interested http://www.eurostemcell.org/files/Human_ES_ethics_1.pdf

Stem cells blog by: Ana Djurica

Stem Cells Blog by: Ana Djuirca

1.What are stem cells?

“Cartman: Doctor, can you tell me exactly how stem cells work?
Doctor: Well you have trillions of cells in your body, heart cells, skin cells, brain cells and so on. But before a cell is designated as a toenail cell, or a pancreas cell, it's what we call a stem cell. Sort of like a blank cell, do you understand?
Cartman: Not at all, but go on.” ("Kenny Dies." - Full Episode. N.p., n.d. Web. 04 Oct. 

Giving it a more scientific definition, according to "Stem Cell Basics." : Introduction [Stem Cell Information]. N.p., n.d. Web. 04 Oct. 2015.  "Stem cells have the remarkable potential to develop into many different cell types in the body during early life and growth. In addition, in many tissues they serve as a sort of internal repair system, dividing essentially without limit to replenish other cells as long as the person or animal is still alive. When a stem cell divides, each new cell has the potential either to remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell, or a brain cell. Until recently, scientists primarily worked with two kinds of stem cells from animals and humans: embryonic stem cells and non-embryonic(adult)."

2. What are similarities and differences between embryonic and adult stem cells?

Regarding the therapeutic purposes, both types have their advantages and disadvantages. One big difference between embryonic and adult stem cells is in their different abilities in the number and type of differentiated cell types they can become. Embryonic stem cells can become any kind of cell type in our body because they are pluripotent¹, adult stem cells are limited to differentiating into different cell types of their tissue of origin. The use of adult(non-embryonic)stem cells and tissues derived from the patient's own adult stem cells would mean that the cells are less likely to be rejected by the immune system. This is a major advantage.

3. What are the purposes of stem cells?

According to "Stem Cell Basics." : Introduction [Stem Cell Information]. N.p., n.d. Web. 04 Oct. 2015. ,“Perhaps the most important potential application of human stem cells is the generation of cells and tissues that could be used for cell-based therapies. Today, donated organs and tissues are often used to replace ailing or destroyed tissue, but the need for transplantable tissues and organs far outweighs the available supply. Stem cells, directed to differentiate into specific cell types, offer the possibility of a renewable source of replacement cells and tissues to treat diseases including macular degeneration, spinal cord injury, stroke, burns, heart disease, diabetes, osteoarthritis, and rheumatoid arthritis.”

4. Something interesting to add about stem cells?

Yes, a lot of it actually. 

1. Third source of stem cells. According to"Online Biology Degree." Online Biology Degree RSS. N.p., n.d. Web. 04 Oct. 2015.  "Embryo or adult aren’t the only two places one can get stem cells. Blood used from the umbilical cord made during pregnancies is also a good source. And the results can be impressive. In 2006, researchers at the University of Minnesota announced they were able to largely reverse the effects of strokes in lab rats using stem cells found in human umbilical cord blood."
2. States still CAN decide. Although the federal government might have agreed on research of stem cells, each and every one of the 50 states in the US is free to pass their own laws. Ex: in 2010 Minnesota changed it's ban on paying scientists to engage in all forms of human cloning. The University of Minnesota was a major supporter of the funding and announced that by destroying the organism 5-10 days after making it, that it's not cloning.
3. Stem cells in space. It is widely know that astronauts with their return to Earth, have problems with regeneration of their mucle tissue. They are really weak and they need a lot of time to recover from the journey. NASA think that it might just be stem cells, that can help them in the process of recovery from the "trip". 

5. Stem cell joke? 

Yep.

And the above interesting facts you may not know about stem cell research are just the beginning to debates and future decisions on the topic. With so much more to be learned from the benefits versus the cost of stem cell research, there is still more to be said and discovered.

Stem Cell - Aron

Stem Cells

The properties of stem cells were discovered by scientists in 1998. Stem cells are used by organisms to create different cells during the first stages of life, and they are also used to regenerate tissue and to create blood cells (Allott pg.12-13). For example, the stem cells of a developing zygote will separate, and each group will reproduce to create a certain cell type for bodily functions (muscle cells, brain cells, heart cells, etc.). Even though stem cells will branch out to create differentiated cells after the zygote starts to develop, stem cells can still be found in areas such as the bone marrow in adults. To be more specific, adults have stem cells in their: bone marrow, skin, heart, brain, liver, and kidneys(Allott pg.12-13). The problem with the stem cells in adults are that certain organ stem cells (heart, brain, and kidney) can only help regrow tissue to a certain extent(Allott pg.12-13).

Stem cells can be used for a variety of outcomes which may benefit the human race. One prominent example, which stuck out to me, was that stem cells can be used for consumption (figure #1). Scientists can actually grow edible muscle fibres from stem cells(Allott pg.13). I find this to be very beneficial, because of the time it takes to raise animals and the ethical arguments against slaughtering animals. When people harvest meat from animals, they will leave most of the animal’s internal organs. For example, when I watched my dad gut a fish, he basically threw away every organ while leaving the muscle fibres and skin. “Why would an animal life be extinguished for food, even though people end up tossing away the good bits” (Aron, 2015, a day before this is due (great quotes of our time)).

Figure #1- The first ‘stem cell burger’

Stem cells can also be used for health issues, and I will explain their uses in Heart disease and Leukemia. Heart disease is defined when heart muscles start to deteriorate because the muscles of the heart are not receiving enough oxygen. According to the ‘National Institutes of Health’, stem cells that are believed to help with this disease are: embryonic stem cells, certain stem cells from the bone marrow (mesenchymal cells), and stem cells taken from the umbilical cord. These stem cells could possibly regrow the damaged muscle brought by Heart disease. Stem cells can help with Leukemia due to the effects of Chemotherapy. Allott states that the effects of Leukemia are an overproduction of white blood cells (Allott pg.14). While Chemotherapy will destroy all of these white blood cells, it will also end in the extermination of stem cells in the marrow(Allott pg.14). If the stem cells in the bone marrow were eradicated, the certain individual would have a hard time with his immunity. Now, you may be wondering why I am saying stem cells are good in this situation. You may be saying “Aron, stem cells are keeping us from healing chemotherapy,”, but scientists have found a way around this. The boys at Oxford University Press (Allott/Mindorff) explain that doctors will suck out the stem cells from one of the body’s bigger bones (usually the pelvis)(Allott pg.14). The doctors will insert the stem cells back into the patient’s bone, so the body will start producing white blood cells to strengthen immunity (Allott pg.14). So without stem cell research, Chemotherapy would be a very dangerous task to undergo.

Figure #2- Removing stem cells from pelvis -”Chemotherapy is a pain in the …” (“Comedy doesn’t work unless someone is getting offended”-George Carlin)

The biggest debates against using stem cells is the destruction of an embryo, and there are some problems that arise from certain types of stem cells. Some people believe that the embryo is technically a living and feeling being, which would be like killing a human child. Ian Murnaghan suggests that there is some controversy to embryo stem cell research, because most practices including stem cells mostly include those from adults . As a different perspective, other individuals believe that embryos do not equate to a human child. I can vouch for this perspective, because the human society makes me believe that this is true. For example, if life really began when you were an embryo, then why don’t you count those 9 months to your age. Another example can be from a TOK class, where I was told that the child could be considered as part of the mother until the umbilical cord is cut. Allott and Mindorff suggest that embryonic stem cells could be more likely to turn into tumor cells (Allott pg.15). They also suggest that embryonic cells have a high chance of being genetically different from the recipient (Allott pg.15). This may be a problem when dealing with immunity, where white blood cells will attack any cells that are unfamiliar. While there may be some good arguments against stem cell research people “Must not forget ethical arguments in favour of the use of embryonic stem cells,”, which is a quote from the book by Allott and Mindorff. They make a good point, because stem cell research can be used to benefit the lives of others with diseases, or if they are living in an area with a low potential for animal husbandry.

Bibliography

- Murnaghan, Ian. "Stem Cell Controversy." Stem Cell Controversy. Web. 4 Oct. 2015.<http://www.explorestemcells.co.uk/stemcellcontroversy.html>.

-Allott, Andrew, and David Mindorff. "Cell Biology." Biology. 2014 Edition ed. Oxford: Oxford UP, 2014. Print.

- Mandal, Ananya. "What Are Stem Cells?" News-Medical.net. 10 Jan. 2010. Web. 4 Oct. 2015.<http://www.news-medical.net/health/What-are-Stem-Cells.aspx>.

- "Stem Cell Basics." What Are the Potential Uses of Human Stem Cells and the Obstacles That Must Be Overcome before These Potential Uses Will Be Realized? [Stem Cell Information]. National Institutes of Health. Web. 4 Oct. 2015. <http://stemcells.nih.gov/info/basics/pages/basics6.aspx>.