Bevington 5

Question 1

Types of stem cell

Answer 1

Embryonic (Many different lineages)

Adult (Committed to a particular lineage)

Question 2

Example of adult stem cell differentiation pathway

Answer 2

Connective tissue cells ‘fibroblasts’

• Differentiation by embryogenisis
• go on to differentiate to many types of tissue e.g. adipose, cartilage, bone

Question 3

Significance of asymmetry of stem cells? Transit amplifying cells?

Answer 3

2 daughter cells form -> one can specialise and one can be used for ‘self-renewal’
- committed specialising daughter cell can further divide to form many terminally differentiated cells in ‘transient amplification’ process

Question 4

What is the main problem regarding differentiation with animal cells in culture?

Answer 4

Limited differentiation or even de-differentiation

- cells in culture do not fully differentiate and can even de-differentiate into more unspecialised cells

Question 5

Whats factors affect differentiation?

Answer 5

Soluble factors e.g.
- Vitamins, Hormones, Cytokine proteins
Extraceullar matrix

Question 6

What is the molecular basic of cell differentiation?

Answer 6

Cells express particular phenotypes dependant on particular expressed genes in its genome

Question 7

Define:
Genome
Transcriptome
Proteome

Answer 7

Genome = Set of genes present in a cell
Transcriptome = Set of mRNA expressed in a cell
Proteome = Set of proteins expressed in a cell

Question 8

2 ways DNA can be altered causing cells to commit to a cell lineage

Answer 8

• Genetic mutation, e.g. in B Lymphocytes
• Epigenetics, DNA sequence the same but DNA or chromatin biochemically tagged in some way e.g. methylation of cytosine bases