stem cells and differentiation

Question 1

properties of stem cells

Answer 1

Self-renewal: the ability to go through numerous cycles of cell growth and cell division, known as cell proliferation, while maintaining the undifferentiated state.

Potency: the capacity to differentiate into specialized cell types.

Question 2

symmetric division

Answer 2

Symmetric division:refers to cell replication in which both daughter cells can either be identical to the parent cell or different, with a more restricted potential

Question 3

asymmetric division

Answer 3

Asymmetric division:refers to cell replication in which one daughter cell enters a differentiation pathway and gives rise to mature cells, while the other remains undifferentiated and retains its self-renewal capacity.

Question 4

stem cell potency- totipotent

Answer 4

Totipotent – cells able to differentiate in any other cell type; generate all the tissues of the embryo and the extra-embryonic tissue.

Question 5

stem cell potency- pluripotent

Answer 5

Pluripotent – can develop into cells of one of the three primary cell layers, i.e. ectoderm, endoderm and mesoderm

Question 6

stem cell potency

Answer 6

Multipotent – ability to differentiate into multi-lineages but not to all germ layers

Question 7

stem cell potency- unipotent

Answer 7

Unipotent – are the most restricted in their differentiation potential, as they can only give rise to a single cell type, although they still retain the capacity for self-renewal.

Question 8

human embryonic stem cells

Answer 8

• able to become any of the 200 types of cells within the body
• extremely controversial
  pluripotent
• rejection problems- will be attacked by recipients immune system
  -easier to culture and expand

Question 9

adult stem cells

Answer 9

• multipotent
• able to become specialised cell types within the residing tissue or specific cell type of the tissue
• less controversial
• difficult to culture and expand
• useful for transplants can be allogeneic/autologous

Question 10

haematopoetic system cells

Answer 10

-Found mainly in the bone marrow;
Identified by the presence of specific markers (cKIT and CD34);

Question 11

haematopoetic stem cells differentiation

Answer 11

common myeloid progenitor- megakarycocyte, erythrocytes, mast cells, myoblasts- basophil, neutrophil, eosinophil, monocytes- macrophages

common lymphoid progenitor- natural killer cell, small lymphocytes- t lymphocyte, b lymphocytes- plasma cell

Question 12

syngeneic

Answer 12

• genetically identical

Question 13

allogeneic

Answer 13

genetically dissimilar

Question 14

autologous

Answer 14

• uses a persons own stem cells