Cells and control Study Guide

Stem cells are undifferentiated cells with the ability to develop into various types of specialised cells. In animals, these can be broadly categorised into embryonic stem cells and adult stem cells. Embryonic stem cells, found in the early embryo, are pluripotent, meaning they can differentiate into any cell type of the body. They have significant potential for therapeutic uses, such as repairing damaged tissues or organs. Adult stem cells, found in various tissues throughout the body, are multipotent or unipotent, meaning they can differentiate into a limited number of cell types to repair and maintain those specific tissues. Examples include bone marrow stem cells forming blood cells or skin stem cells renewing skin. In plants, meristems are regions of unspecialised cells capable of cell division and differentiation. Apical meristems, located at the tips of roots and shoots, are responsible for primary growth (increase in length). Lateral meristems, such as the vascular cambium, are responsible for secondary growth (increase in girth). These meristematic cells enable plants to grow continuously throughout their life and to replace damaged parts.

Stem cells are undifferentiated cells with the potential to develop into many different cell types. Their unique ability to self-renew and differentiate makes them highly valuable in medical research and therapies. Benefits include their use in treating diseases like Parkinson's, spinal cord injuries, and diabetes by replacing damaged cells or tissues. They also offer a powerful tool for drug testing and understanding disease development. However, several risks and ethical considerations are associated with stem cell use. These include the potential for immune rejection if the cells are not from the patient themselves, the risk of tumour formation if differentiation is not controlled properly, and the ethical concerns surrounding the use of embryonic stem cells due to the destruction of an embryo. Sourcing stem cells, particularly embryonic ones, raises significant moral debates in society. Furthermore, the practical challenges of growing and controlling stem cell differentiation accurately in a laboratory setting are complex.