Stem cells
Find out where stem cells come from and how they are used in humans and plants
Stem cells in humans
A cell found in foetuses, embryos and some adult tissues that can give rise to a wide range of other cells. are cells that have not undergone When an unspecialised cell becomes a more specialised cell type.. A cell which has not yet become A cell that has become differentiated to carry out a particular function, eg red blood cell. is called undifferentiated.
An An organism in the early stages of development. develops from a fertilised egg. Cells at the early stages in the development of the embryo are stem cells.
If cells are removed from the embryo 鈥 called A type of stem cell found in the embryo, capable of dividing into almost any cell type. - they will differentiate into any cell type.
Some stem cells remain in the bodies of adults 鈥 A type of stem cell found in specific locations in adults. Adult stem cells can only differentiate into a limited number of related cell types.. Adult stem cells are found in limited numbers at certain locations in the body.
Adult stem cells can be found in several regions of the body, including the:
- brain
- eyes
- blood
- heart
- liver
- bone marrow
- skin
- muscle
Adult stem cells can differentiate into related cell types only, for example, Soft tissue found inside bones that produces new blood cells. cells can differentiate into blood cells and cells of the The body's defence system against entry of any foreign body, including pathogens and agents such as pollen grains. The role of the immune system is to prevent disease. but not other cell types.
Medical treatments with stem cells can help conditions such as A medical condition in which the hormone insulin cannot be produced or stops working, resulting in high levels of glucose in the blood. and Being unable to move all or part of a person鈥檚 body because of illness or injury.. An embryo can be produced with the same genes as the patient in a process called Making a cloned embryo to produce embryonic stem cells with the same DNA as the donor cell.. These stem cells will not be rejected by the person receiving them, so they can be used for medical treatments. There are some risks using stem cells for medical treatments such as the transfer of viral infections. Some people also have ethical concerns or religious objections to their use.
Stem cells in plants
Cell division in plants occurs in regions called A region in plant shoots and roots in which cells are dividing, and so are undergoing mitosis..
Cells of the meristem can differentiate to produce all types of plant cells at any time during the life of the plant.
The main meristems are close to the tip of the shoot, and the tip of the root.
In a growing shoot, new cells are being produced continuously near the tip. As the cells become older, further away from the tip, they become differentiated 鈥 they enlarge and develop A space within the cytoplasm of plant cells that contains cell sap..
Stem cells from the A region in plant shoots and roots in which cells are dividing, and so are undergoing mitosis. of plants can be used to make clones of plants quickly and cheaply. This can help endangered species close to extinction. This can also make crops that are resistant to diseases and pests, and produce large numbers of genetically identical plants.
Discover more about stem cells with Dr Alex Lathbridge
Listen to the full series on 大象传媒 Sounds.
Discover how cells differ in plants and animals and why they're really useful for scientists.