Stem cells

To define stem cells.
To compare and contrast embryonic stem cells, adult stem cells, and plant meristem cells in terms of their location and differentiation potential.
To discuss the potential uses and ethical considerations of stem cells in medicine and agriculture.

Stem cells are undifferentiated cells that have the unique ability to develop into various cell types.
They can divide to produce more stem cells or differentiate to form specific types of cells, each with a particular function.

Embryonic Stem Cells (in Animals):
- Found in embryos, which form when a sperm fertilises an egg.
- Can be cloned and made to differentiate into almost any type of human cell.
- This makes them valuable for potential treatments for conditions such as diabetes and paralysis.
Adult Stem Cells (in Animals):
- Located in certain tissues like bone marrow.
- Can differentiate into a limited range of cell types, such as blood cells.
- They are often used to treat conditions affecting the same tissue or organ, for example, using bone marrow stem cells to treat blood disorders.
Meristem Stem Cells (in Plants):
- Found in the meristem tissue at the tips of plant shoots and roots.
- Unlike animal stem cells, meristem cells can differentiate into any type of plant cell throughout the plant's life, aiding in growth and regeneration.

Therapeutic cloning is a process where an embryo is created with the same genetic makeup as the patient.
This allows stem cells derived from the embryo to be used in treatments without being rejected by the patient’s immune system.
This technique shows promise in treating conditions like diabetes (by replacing damaged pancreatic cells) and paralysis (by repairing spinal cord injuries).

The process of therapeutic cloning.

In plants, stem cells are found at the very tip of the stem and the root - these are known as meristems.
Plant stem cells from meristems are used to produce clones of plants efficiently and cost-effectively. For example:
- Conservation: Cloning rare plant species can help prevent extinction.
- Agriculture: Crop plants with desirable traits, like disease resistance, can be cloned to produce uniform and reliable crops for farmers.
However, a downside to plant cloning is that all clones are genetically identical, making them equally susceptible to specific diseases.

Stem cells: Undifferentiated cells that can divide to produce more stem cells or differentiate into specialised cells.
Undifferentiated: Not yet specialised to perform a particular function.
Differentiate: The process by which a cell becomes specialised.
Embryonic stem cells: Stem cells found in embryos that can differentiate into almost any cell type.
Adult stem cells: Stem cells found in certain mature tissues that can differentiate into a limited range of cell types.
Meristem stem cells: Stem cells found in plant meristem tissue that can differentiate into any plant cell type throughout life.
Therapeutic cloning: A process to create an embryo genetically identical to a patient for generating compatible stem cells.
Clones: Genetically identical copies of an organism or cell.

Ethical Debate Prep: Research the ethical arguments for and against the use of embryonic stem cells in therapeutic cloning. Prepare points for both sides of a debate.
Stem Cell Application Case Study: Choose one disease or condition (e.g., Parkinson's, spinal cord injury) where stem cell therapy is being researched or used. Investigate the current progress, challenges, and potential future of this treatment.