Stem Cells Flashcards
Stem cell:
An undifferentiated/unspecialised cell which an self-renew to produce more cells of the same type or
specialise to carry out a specific function
Unspecialised cells:
• They can become any type ofcell
• stem cells
Specialised cells:
• These cells are fixed
• They can onlydivide to make its own type of cell
When do plant stem cells differentiate?
Many plant cells retain the ability to differentiate throughout their lives
Where are plant stem cells found?
• Plants have layers of unspecialised stem cells in the roots and shoots
• The layers are called the meristem
What can the meristem tissue in plant cells differentiate into?
Meristem tissue in plants can differentiate into any type of plant cell, throughout the life of the plant
Why are plant stem cells useful
• Stem cells from meristems in plants can be used to produce clones of plants quickly and economically
• Rare species can be cloned to protect them from extinction
• Crop plants with special features such as disease
resistance can be cloned to produce large numbers of identical
plants for farmers so more crops can survive
What are all the types of human stem cells?
• Embryonic stem cells
• Umbilical stem cells
• Adult stem cells
• Therapeutic stem cells (therapeutic cloning)
Where are embryonic stem cells found?
Developing cells of an embryo (3-5 days old)
What can embryonic stem cell differentiate into?
Any type of cell
What are the positives of embryonic stem cells?
• Can differentiate into any type of cell
• [Uses ‘wasted’ embryos from
IVF]
• All types of tissues can be grown
• Replace cells that have been damaged or destroyed e.g. paralysis
What re the negatives of embryonic stem cells?
• Ethical issues - destroying the embryo and therefore a chance of life
• Need to take
immunosuppressant drugs
• Technology is still developing
• Expensive
Where are umbilical stem cells found?
In the umbilical cord after the birth of a child
What can umbilical stem cells differentiate into?
Blood cells - often used to treat blood disorder in the child later in life
Where are adult stem cells found?
most parts of the body, including brain, bone marrow, blood vessels
What can adult stem cells differentiate into?
all of the cells of the adult body
What are the negatives of adult stem cells?
may not be able to be manipulated to produce all cell types
What are positives of therapeutic stem cells?
regenerate functional tissue and replace damaged tissue
What can stem cells be used to treat in medicine?
leukemia, Hodgkin disease, non-Hodgkin lymphoma and some solid tumor cancers
Why is therapeutic cloning less ethically wrong than destroying embryonic stem cells?
destruction of the generated embryos in order to collect cells that would further be differentiated in vitro
What has led to the development of stem cell technology?
Embryonic stem cells were first isolated in 1981 through studies focusing primarily on murine blastocysts
