Stem cells 2.1.6 (j,k,l,m) Flashcards
what is the process of a cell becoming specialised?
differentiation
what is a stem cell?
an undifferentiated cell which can differentiate into a range of specialised cell types
what can a differentiated cell not do?
re-enter the cell cycle
so it cannot divide
why are stem cells important?
they are a source for new cells needed for:
- growth
- development
- tissue repair
what are the three types of cell potency?
totipotent
pluripotent
multipotent
what is potency?
a stem cell’s ability to differentiate
what is totipotent?
a stem cell can differentiate into any type of cell
what is pluripotent?
a stem cell can differentiate into all tissue types but not whole organisms
what is multipotent?
a stem cell can only differentiate into a range of cells in a specific tissue
where are blood cells derived from from?
the bone marrow
what happens at the bone marrow?
adult stem cells divide and differentiate to replace worn out blood cells:
- erythrocytes
- neutrophils
what are the sources of animal stem cells?
- embryonic stem cells
- adult stem cells
what are embryonic stem cells?
found in the embryo
are totipotent from early on
after 7 days they become pluripotent
what are adult stem cells?
found in the bone barrow
are multipotent
what is the source of stem cells in plants?
meristematic tissue
where is meristematic tissue found?
between the phloem and xylem
what are the properties of stem cells in the meristematic tissue?
pluripotent
can differentiate into xylem and phloem cells
what are the uses of stem cells?
- treating diabetes
- treating Alzheimers
- treating Parkinsons
- developmental biology
how are stem cells used to treat diabetes?
stem cells are differentiated into beta cells which can replace damaged beta cells and allow for insulin to be produced
how are stem cells used in developmental biology?
they are used to study how organisms grow and develop
what ethical issues surround the use of embryonic stem cells?
to harvest embryonic stem cells, the embryo must be destroyed
many people view the destruction of embryos as murder as people see the creation of an embryo as the start of life
