Stem Cells

Question 1

Define a Stem cell

Answer 1

Immature, undifferentiated, non-specified cell with the capacity for prolonged or unlimited self-renewal.
Can differentiate to produce at least one type of cell/tissue

Question 2

Define Totipotent

Answer 2

Form all tissues of an organism including extra embryonic membranes and tissues - fertilised egg

Question 3

Define Pluripotent

Answer 3

Capable of giving rise to most tissues - embryonic stem cells, induced pluripotency stem cells

Question 4

Define Multipotent

Answer 4

Adult stem cells capable of forming restricted number oc cell types. Haematopoietic, Mesenchymal, Cord blood

Question 5

Define Unipotent

Answer 5

One cell type - spermatogenesis

Question 6

Describe process of Asymmetric division

Answer 6

Stem cell divides to give 2 daughter cells, 1 is identical to parent cell - other is slightly changed.
Progenitor cells have a finite number of times they can divide.

Question 7

What is Apoptosis

Answer 7

Natural form of cell death - fundamental to tissue modelling

Question 8

Requirements of stem cells

Answer 8

Recapitulate tissue morphogenesis
Generate adequate cell population/tissue size
Maintain specific phenotype/function
Appropriate 3D organisation
Prevention of immune-rejection
Vascularisation

Question 9

Mature stem cells

Answer 9

Easily obtained, no need for immune-suppression.
Poor growth/difficult to get enough
Change phenotypic characteristics.
Prolonged morbidity
2 wound sites

Question 10

Advantages and Disadvantages of adult stem cells from bone marrow

Answer 10

A = Various cell types, your own, rapid and no immunincompatability
B = Sparse/very controlled, propagate and transmit harmful disease/numbers and potency diminish with age

Question 11

Advantages/disadvantages of embryonic stem cells

Answer 11

Advantages - any cell type in the body, genetic manipulation, beneficial/therapeutic genes, modulate/controle immunotolerance
Disadvantages - can’t accurately control differentiation, ethics, destruction of embryo, stability and transmission of disease

Question 12

What are the three types of cloning

Answer 12

1) Cell -Genetically identical
2) Therapeutic - Reprogramming nucleus of adult cell by transfer to cytoplasm of enucleated oocyte. Isolating ES cells after formation of blastocysts.
3) Reproductive - ‘’ reimplanting embryo to enable formation of viable foetus

Question 13

What are IPS cells

Answer 13

Reprogramming differentiated cells from adult tissues to a less differentiated, pluripotent state.
Introducing/transducing genes associated with pluripotecy into differentiated cells using viruses
Low efficacy
Distinct cell types

Question 14

Four types of graft

Answer 14

1) Autografts - from patients own body, transplanting to another site
2) Allografts - from a donor into another patient
3) Xenografts - tissue and organs from animals into human
4) Man-Made - artificial