4 2 2 STEM CELLS BUTTONS Clicking here

4. 2. 2 STEM CELLS BUTTONS Clicking here will allow you hear information on the Clicking some information. back asome page. move to theto next Clicking here will reveal antoanswer. Clickingherewillreveal bring you this page. topic. Clicking here again will stop the sound. TOPICS Jump to … … the embryo and stem cells (2 pages). Jump to … … medical uses of stem cells (5 pages). Jump to … … use of stem cells in plants (1 page). Jump to … … practice question (1 page). Jump to … … examination questions (3 pages).

THE EMBRYO AND STEM CELLS The young embryo contains stem cells, which are undifferentiated cells. These continue to divide through MITOSIS and eventually will begin to differentiate into all the specialised cells needed to make a new organism. Embryo Stem cells

DIFFERENTIATION Click here to begin MUSCLE CELLS ION IAT ENT DIFFERENTIATION DIFF ERE WHITE BLOOD CELLS DIF NTIA TION SEX CELLS STEM CELL DIF FER DIFFER EN ENT IAT ION N TIATIO It is possible for any stem cell to develop into any specialised cell in the body. FER RED BLOOD CELLS BONE CELL

MEDICAL USES OF STEM CELLS In a laboratory it’s possible to produce an embryo in order to use the stem cells to treat medical conditions. Stem cell BURN INJURIES by growing new skin to repair damaged skin CURE BLOOD DISEASES by growing healthy red or white blood cells CURE DIABETES by growing healthy pancreatic cells which can produce insulin to be transplanted into the patient

TWO PROBLEMS WITH USING STEM CELLS FROM AN EMBRYO ETHICAL ISSUES Producing a human embryo to be used as a source of stem cells has been a very controversial subject. Any human embryo could have developed into a human being. REJECTION PROBLEMS If stem cells are used in a patient, their immune system will reject the stem cells. It would be better to collect stem cells from the patients’ own bodies.

MEDICAL USE OF A PATIENT’S OWN STEM CELLS Mature humans do have a few stem cells – found in the skin , which grow new skin when the skin is damaged. Click here to begin. e. g. If there is a severe injury, scientists can collect the patient’s own stem cells, grow them in a laboratory and use them to replace the damaged tissue. Severe burn injury. New skin can be transplanted back to the patient’s body to heal the burnt skin. Medics collect a small area of skin which contain stem cells from another area of the body. In the laboratory the stem cells develop enough new skin to form skin tissue.

ANOTHER MEDICAL USE FOR STEM CELLS IN A PATIENT Click here to begin. To repair eye conditions like blindness, doctors collect stem cells from the patient, grow them in the laboratory, and inject them back into the diseased eye. The stem cells will differentiate into the specialised cells of the eye, curing the blindness. Collect stem cells from the patient Because the cells come from the patient, their body does not reject them. Place them to grow in a Petri dish Inject the stem cells into the correct region of the eye The stem cells differentiate into eye cells, repairing the vision problem.

ADVANTAGES OF USING THE PATIENT AS A SOURCE OF STEM CELLS (rather than using a donor) 1. They will not be rejected ( the immune system recognises them as coming from their own body). 2. There is no need to find a suitable donor. 3. There is no need for tissue typing. Find the correct term to fill the blank spaces. Click to check your answers. At one time, the only source of stem cells was an embryo , but this gave rise to specific ethical issues e. g. collecting cells from an embryo destroyed it, the embryo could have developed into a human.

THE USE OF STEM CELLS IN PLANTS. cuttings Click here to begin Its possible to make cuttings of a rose bush in order to grow more of the same. A cut stem can grow new roots and leaves. MOTHER PLANT Four new rose bushes grew from the original cuttings. Each one will be a clone of the mother plant, they are genetically identical to it. Plant grown from a cutting = CLONE

EXERCISE QUESTION Click only on the correct statements below: A stem cell is one which has not differentiated. Every cell in an embryo is a stem cell. Stem cells will differentiate into specialised cells. There are many stem cells in an adult body. Stem cells in plants allow gardeners to grow roots on shoot cuttings. Embryonic stem cells can be used to cure diabetes. A red blood cell can be used as a stem cell By growing stem cells from a patient their medical condition can be cured. A nerve cell has not differentiated.

WJEC Biology 2 Found/ Higher Summer 2018 EXAMINATION QUESTION 1 Try and answer this examination question. Once you have answered, click examiner’s response. to see the 1. Because after traditional surgery its possible to stand relatively quickly ( although the bone has not repaired) 2. Stem cells repair the bone faster / less treatment needed – no metal rod or screws. 2 46 They have to : differentiate / develop into bone cells. Continue to next slide

cancer Some think that it is unacceptable ( or wrong) to use stem cells from an embryo for treatment because it destroys a human life.

EXAMINATION QUESTION 2 WJEC BIOLOGY 2 Higher, Jan 2015 Try and answer this examination question. Once you have answered, click to see the examiner’s response. The stem cells were collected from a human embryo. Stem cells