stem cells Flashcards
what did all specialised cells originally come from
stem cells
what are stem cells
unspecialised cells that can develop into other types of cell which then divide to become specialised
where are stem cells found
in the embryo and in some adult tissues
what is a totipotent cell
a stem cell that can mature (develop) into any type of body cell in an organism.
they are only present in mammals
where are totipotent cells present in
only mammal cells
what is a pluripotent cell
a stem cell that can develop into any type of cell, apart from the cells that are made in the placenta
what is a multipotent cell
a stem cell that is only able to develop into a few types of cell
what is a unipotent cell
a stem cell that can only differentiate into one type of cell
what is an induced pluripotent cell
IPS is a pluripotent type of stem cell made in the lab by reprogramming a specialised adult body cell to express certain transcription factors
what is differentiation
the process by which a stem cell becomes a specialized cell type
why do stem cells become specialized and when
during their development they only transcribe and translate part of their DNA
what happens to the genes that are expressed
the get transcribed into mRNA which is then translated into proteins
the expressed genes get transcribed into mRNA which is then translated into proteins what do the proteins do
modify the cell
the expressed genes get transcribed into mRNA which is then translated into proteins what do the proteins determine
they determine the cell structure and control cell processes
what does the change to the cells produced by these proteins cause the cell to become
specialised
what are these changes difficult to do
reverse them
explain what happens when a gene is expressed (full)
gene is expressed
mRNA transcribed and translated into proteins
proteins modify the cell
cell becomes specialised for a particular function
explain what happens when a gene is switched off
genes switched off
mRNA not translated or transcribed
proteins are not produced
what are cardiomyocytes
heart muscle cells that make up a lot of tissues in our cells
can cardiomyocytes be replaced explain
yes, they can be replaced by new cardiomyocytes derived from a small supply of unipotent stem cells in the heart
what does differentiation do
replaces dead or damaged cells throughout your life
explain about differentiation
it is the process of being specialised
