Stem Cells Noadswood Science, 2016

Stem Cells To describe what stem cells are and how they can be used Thursday, November 15, 2018 To describe what stem cells are and how they can be used

Precise Learning A stem cell is an undifferentiated cell of an organism which is capable of giving rise to many more cells of the same type, and from which certain other cells can arise from differentiation. Students should be able to describe the function of stem cells in embryos, in adult animals and in the meristems in plants. Stem cells from human embryos can be cloned and made to differentiate into most different types of human cells. Stem cells from adult bone marrow can form many types of cells including blood cells. Knowledge and understanding of stem cell techniques are not required. Treatment with stem cells may be able to help conditions such as diabetes and paralysis. In therapeutic cloning an embryo is produced with the same genes as the patient. Stem cells from the embryo are not rejected by the patient’s body so they may be used for medical treatment (evaluate the practical risks and benefits, as well as social and ethical issues, of the use of stem cells in medical research and treatments) The use of stem cells has potential risks such as transfer of viral infection, and some people have ethical or religious objections. Stem cells from meristems in plants can be used to produce clones of plants quickly and economically Rare species can be cloned to protect from extinction Crop plants with special features such as disease resistance can be cloned to produce large numbers of identical plants for farmers.

Stem Cells Embryonic stem cells can turn into any type of cell (they are undifferentiated and can develop into different types of cell depending upon the instructions they’re given) Stem cells are found within human embryos (adults do have stem cells but they are only found in a few places such as bone marrow and are not as versatile as embryonic stem cells)

Stem Cells & Disease Medicine has for many years used stem cells (e.g. sickle cell anaemia is treated by bone marrow transplants) Embryos can have their stem cells extracted and grown specifically for medical purposes, such as… To develop into heart muscle for heart disease To develop into insulin producing cells for diabetes To develop into nerve cells for paralysed individuals The research remains in its infancy, but the possibilities for medical improvements are vast…

Medicine Embryonic stem cells could be used to replace faulty cells in sick people In therapeutic cloning an embryo could be produced to contain the same genetic information as the patient – this means that the stem cells produced from it would also contain the same genes as the patient and so wouldn’t be rejected

Plants In plants stems cells are found in meristems (parts of the plant where growth occurs) Throughout the plants entire life cells in the meristem tissues can differentiation into any type of plant cell – they can be used to quickly produce clones (useful for growing identical crops / a specific endangered species etc…)

Negative Press Some individuals are against stem cell research because they feel human embryos should not be used (as they can potentially become a human life) The counter to this is stem cells can sure patients who already exist and are suffering already Embryos used in research are normally unwanted ones from fertility clinics, which if they were not used for research would be destroyed… Stem cell research is allowed in the UK, though it must adhere to strict guidelines

Risks There are risks involved with stem cells – when grown in the laboratory they may become contaminated with viruses which could potentially be passed to the patient (as well as ethical issues) Research the benefits / controversies of stem cells using either the laptops or the printed documents and form a piece of opinionated writing for one way or the other…

https://youtu.be/cEB8656TCIE Stem Cells https://youtu.be/cEB8656TCIE

Practice Questions What is a stem cell? What type of cell can early embryonic stem cells turn into? Give one place where stem cells can be found in an adult human Why could embryonic stem cells produced by therapeutic cloning be useful for replacing faulty cells in a sick person? Name the tissue in plants where stem cells can be found

Answers What is a stem cell – an undifferentiated cell that has the potential to differentiate into different types of cell What type of cell can early embryonic stem cells turn into – any type of cell Give one place where stem cells can be found in an adult human – bone marrow Why could embryonic stem cells produced by therapeutic cloning be useful for replacing faulty cells in a sick person – they would be genetically identical (no rejection) Name the tissue in plants where stem cells can be found – meristem

Practice Questions Application Alzheimer’s disease is a condition which damages the neurons (nerve cells) in the brain. These neurons die, but are not replaced, leading to a decrease in the amount of neurons in the brain. Symptoms of Alzheimer’s disease include memory loss, confusion and changes in personality. Suggest a way in which embryonic stem cells could potentially be used to treat people with Alzheimer’s disease and give another possible use of embryonic stem cells in medicine.

Answers Alzheimer’s disease is a condition which damages the neurons (nerve cells) in the brain. These neurons die, but are not replaced, leading to a decrease in the amount of neurons in the brain. Symptoms of Alzheimer’s disease include memory loss, confusion and changes in personality. Suggest a way in which embryonic stem cells could potentially be used to treat people with Alzheimer’s disease and give another possible use of embryonic stem cells in medicine – stem cells could be made to differentiae into neurons which could replace the damaged / dead neurons. Nerve cells could also be produced to replace damaged nerve cells in paralysed people / insulin for diabetics…

Practice Questions Application II Embryonic stem cells used for medical research are mostly taken from embryos left over from fertility clinics, which would otherwise be destroyed. Suggest a reason why some people are happier with using these embryos for stem cell research rather than creating embryos purely with the purpose of being used for research. Embryos begin to develop a nervous system 14 days after fertilisation. Some people think that it is morally acceptable to use an embryo for stem cell research before this point, as the embryo has no senses, so cannot be considered a life yet. Suggest a reason why some people may not agree with this view.

Answers Embryonic stem cells used for medical research are mostly taken from embryos left over from fertility clinics, which would otherwise be destroyed. Suggest a reason why some people are happier with using these embryos for stem cell research rather than creating embryos purely with the purpose of being used for research – embryos leftover from fertility clinics will be destroyed anyway Embryos begin to develop a nervous system 14 days after fertilisation. Some people think that it is morally acceptable to use an embryo for stem cell research before this point, as the embryo has no senses, so cannot be considered a life yet. Suggest a reason why some people may not agree with this view – the embryo still has the potential to develop into a human life before this point