Lecture 13

Question 1

What is cell determination?

Answer 1

• A process by which a single fertilised cell (Zygote) divides into multiple cells, groups of these cells gradually become committed to specific patterns of gene activity
• A progressive fixation of the fate of a cell’s descendants

Question 2

What are mesenchymal stem cells?

Answer 2

• Undifferentiated mesodermal cells of the embryo which will differentiate into muscle and connective tissue

Question 3

What is differentiation?

Answer 3

A pathway whereby cells make genetic commitments (regarding the differential expression of genes) and gradually restrict the development of the descendants of that cell to a limited set of final tissue types

Question 4

What is cell differentiation?

Answer 4

• The final step leading to cell specialisation

- Once this point is reached the process is irreversible

Question 5

Stem cell?

Answer 5

An undifferentiated cell of either embryonic or adult origin which can undergo unlimited division and give rise to one or several cell types

Question 6

What are the most versatile stem cells?

Answer 6

Zygotes, they produce all of the cell in the body (totipotent)

Question 7

Totipotent stem cells?

Answer 7

Potential to give rise to all tissues of the body and placenta

Question 8

Pluripotent stem cells?

Answer 8

Can give rise to many of the types of cells in an organism, but not all

Question 9

What are the two basic cell types that exist?

Answer 9

Germ Cells and somatic cells

Question 10

Germ Cells?

Answer 10

• Can divide by meiosis and produce a new generation of individuals (sex cells)
• Very first cell to differentiate

Question 11

Somatic cells?

Answer 11

Are all the cells of the body except germ cells

Question 12

Stem cells are potential sources for cell transplantation into patients to treat what serious degenerative conditions?

Answer 12

• Dopamine-producing cells for Parkinson’s Disease
• Insulin-producing cells for diabetes mellitus
• Replacement neurons for spinal cord injury or other types of neurological damage

Question 13

Human reproductive cloning?

Answer 13

Has the goal of producing a newborn human that is genetically identical to another human adult

Question 14

Human therapeutic cloning?

Answer 14

Involves duplication of human ES cells or iPS cells for scientific study or medical purposes

Question 15

Parthenogenesis?

Answer 15

Reproduction from an ovum without fertilisation. It occurs naturally in certain plant species, invertebrate animals and even vertebrates (e.g. somefish, amphibians,reptiles )

Question 16

Bee example of parthenogenesis?

Answer 16

Female eggs are produced sexually, using sperm from a drone father, while the production of further drones (males) depends on the queen (and occasionally workers) producing unfertilised eggs. This means that females (workers and queens) are always diploid, while males (drones) are always haploid

Question 17

Human parthenogenetic stem cell (hpSC)?

Answer 17

• Another type of embryonic stem cell
• Stem cells are created by chemically stimulating the oocytes (eggs) to begin division. The oocytes are not fertilised and no viable embryo is created or destroyed

Question 18

Autologous source?

Answer 18

Coming from the same person

Question 19

Allogeneic source?

Answer 19

Coming from a different person/donor

Question 20

Same DNA?

Answer 20

Nuclear equivalence

Question 21

How do you know that you’re dealing with a line of pluripotential stem cells?

Answer 21

• They can form red blood cells, smooth muscle and neurons

- Tumours can develop and if it contains tissue from each of the 3 germ layers then it’s pluripotent

Question 22

3 germ layers produced by somatic cells?

Answer 22

Endodermal, ectodermal and mesodermal