stem cells Flashcards
what are stem cells
uunspecialised/undifferentiated cells that have the potential to become any cell
how do stem cells replicate
1 specialised cell is formed and another daughter cell remains as a stem cell
how are stem cells rated
by their potency
what is potency
varying capability to differentiate into few or many cells types, depending on where the stem cells are found
what cell is totipotent and for how lomg
a zygote, which is the first cell produced following fertilisation, this cell remains azygote (totipotent) for 3-4 days
what does totipotent mean
stem cell that can differentiate into any cell type including placental cells
what cells and for how long are pluripotent
embryonic stem cells 4 - 5 days after fertilisation. these are found in the early stages of a developing embryo
what is plurpotent
stem cells that can diferentiate into all cell types aside from placental cells
what does multipotent mean
stem cells that can differentiate into a limited number of specialised cell types belonging to a specific tissue or organ
phases of embryonic development
zygote, morula, blastocyst, day 16 gastrulation
what happens at gastrulation
3 multipotent germ layers form: ectoderm, mesoderm, endoderm
what does the ectoderm form
nerves and skin
mesoderm
muscles, blood and bone cells
endoderm
internal organs
