Stem Cells (1.2.3) PDF

Stem Cells (1.2.3) A stem cell is an undifferentiated cell which can undergo division to produce many more similar cells, of which some will differentiate to have different functions. Types of stem cells 1. Embryonic stem cells...

Stem Cells (1.2.3) A stem cell is an undifferentiated cell which can undergo division to produce many more similar cells, of which some will differentiate to have different functions. Types of stem cells 1. Embryonic stem cells Form when an egg and sperm cell fuse to form a zygote They can differentiate into any type of cell in the body Scientists can clone these cells (though culturing them) and direct them to differentiate into almost any cell in the body These could potentially be used to replace insulin-producing cells in those suffering from diabetes, new neural cells for diseases such as Alzheimer’s, or nerve cells for those paralysed with spinal cord injuries 2. Adult stem cells If found in bone marrow they can form many types of cells including blood cells 3. Meristems in plants Found in root and shoot tips They can differentiate into any type of plant, and have this ability throughout the life of the plant They can be used to make clones of the plant- this may be necessary if the parent plant has certain desirable features (such as disease resistance), for research or to save a rare plant from extinction Therapeutic cloning involves an embryo being produced with the same genes as the patient. The embryo produced could then be harvested to obtain the embryonic stem cells. Untitled 1  These could be grown into any cells the patient needed, such as new tissues or organs. The advantage is that they would not be rejected as they would have the exact same genetic make-up as the individual. Benefits vs problems of research with stem cells Benefits Problems Can be used to replace damaged or We do not completely understand the diseased body parts. process of differentiation, so it is hard to control stem cells to form the cells we desire. Unwanted embryos from fertility clinics Removal of stem cells results in destruction could be used as they would of the embryo. otherwise be discarded. People may have religious or ethical Research into the process of objections as it is seen as interference with differentiation. the natural process of reproduction. If the growing stem cells are contaminated - with a virus, an infection can be transferred to the individual. Money and time could be better spent into - other areas of medicine. Untitled 2