Stem cell exam questions

Question 1

Explain why some cells are not able to differentiate into other cell types

Answer 1

They have already differentiated/ specialised
Genes needed for other cell types are switched off
Proteins needed for other cell types cannot be made

Question 2

Explain how bone marrow stem cell differentiates into two different cell types

Answer 2

Epigenetic modification
DNA methylation/ histone acylation
Housekeeping genes remained switched on
Genes needed for other cell type switched off
Genes needed for other cell type switched off
Proteins made specific to cell type

Question 3

Similarities between iPS cells and embryonic stem cells

Answer 3

Both have potential to divide indefinitely
Both have potential to differentiate into a number of cell types

Question 4

Differences between iPS cells and embryonic stem cells

Answer 4

IPS cells were adult cells but embryonic stem cells were taken from the morula
IPS cells have a gene added but embryonic cells do not
There are different/less/no ethical issues with IPS cells
IPS cell will produce patient matched cells but embryonic cells will be antigenic
IPS cells can form adult cells whereas embryonic come from younger

Question 5

State the meaning of the term methylation

Answer 5

Addition of methyl groups to a gene at a CpG site

Question 6

Explain why DNA methylation is involved in the development of an embryo

Answer 6

DNA methylation increases after blastocyst
Genes can be switched off
Causing cell to specialise/differentiate