2.3.5 Stem Cells Flashcards
What does pluripotent mean?
Cells that can develop into all specialised cells in an organism (most cells)
What does totipotent mean?
Cells that can develop into a complete human being (any cell)
What does multipotent mean?
Cells that can develop into a variety of different cell types (limited cells)
How many complete cell cycles are needed to produce eight identical cells?
3 cycles are needed
How long does it take for a blastocyst to form?
5 days after fertilisation
What is a blastocyst?
A hollow ball of cells
What are the cells inside a blastocyst known as?
The 50 cells are known as pluripotent embryonic stem cells
What does differentiated mean?
Specialised
What happens to cells as the embryo develops?
The cells become increasingly differentiated
What 3 things do white blood stem cells develop into?
RBC, platelets, and various sorts of WBC
How are most plant cells totipotent throughout their life?
Many cells can dedifferentiate and then develop into a complete new plant
Where are pluripotent stem cells taken from in medical research?
Pluripotent stem cells are taken from ‘spare embryos’
What is a possible use of stem cells in the future?
They might be used to develop tissues that we could use for transplantation
What is a problem with using stem cells to grow replacement tissue?
The body may reject the tissue
What is therapeutic cloning?
The patient will have diploid cell removed.
The cell nucleus would be fused with an ovum (which has no nucleus).
The result is a diploid cell.
What is another name for therapeutic cloning?
Somatic cell nuclear transfer
What did the HFEA give permission for in 2004?
They gave permission for the use of therapeutic cloning in research
What’s an ethical concern with using multipotent stem cells from adults? Eg bone marrow
There are no real ethical concerns
What do scientists believe to be more valuable than multipotent stem cells?
Pluripotent stem cells taken from embryos
What is the role of the HFEA?
- consider ethical and legal aspects
- decide you can only research up to 14 days
- stop human cloning
- check stem cell sources
