Sources of stem cells Flashcards
Where do blood cells derive from?
stem cells in the bone marrow
What is the effect of having no nucleus on erythrocytes?
the have a short lifespan of around 120 days
they therefore need to be replaced constantly
What is the source of embryonic stem cells?
these totipotent stem cells are present at a very early stage of embryo development
after 7 days a mass of cells, called a blastocyst has formed and the cells are now in a pluripotent state
they remain in the state until the fetus is born
What is the source of tissue (adult) stem cells?
present throughout life from birth
found in specific areas such as bone marrow
they are multipotent, although there is growing evidence they can be artificially triggered to become pluripotent
What is the advantage of harvesting stem cells from the umbilical cords of newborn babies?
there is a plentiful supply
invasive surgery is not needed
they can be stored in case they are needed in the future by the individual
tissues cultured from stem cell would not be rejected in a transplant to the umbilicus’ owner
What is the source of plant stem cells?
present in the meristematic tissue (meristems) in plants, this tissue is found wherever growth is occurring in plants, e.g. tips of roots and shoots (termed apical meristems)
What is the vascular cambium? Why is it needed?
meristematic tissue sanwiched between the phloem and xylem
cells originating from this region differentiate into the different cells present in the xylem and phloem tissues
it is needed so vascular tissue grows as the plant grow
