2.6.9 stem cells & their potential uses

Question 1

stem cell

Answer 1

unspecialised cell able to express all of its genes & divide by mitosis

Question 2

characteristics of stem cells

Answer 2

• undifferentiated cells
• described as pluripotent
• able to express all genes
• able to divide by mitosis

Question 3

4 sources of stem cells

Answer 3

1. embryonic stem cells
2. stem cells in umbilical-cord blood
3. adult stem cells
4. induced pluripotent stem cells

Question 4

where are embryonic stem cells found

Answer 4

present in early embryo - formed when zygote begins to divide

Question 5

where are adult stem cells found

Answer 5

found in developed tissues - eg. blood, brain, muscle, bond, adipose tissue & skin (amongst differentiated cells)

Question 6

how are induced pluripotent stem cells developed

Answer 6

in laboratories by reprogramming differentiated cells to switch on certain key genes & become undifferentiated

Question 7

(research/medicine) bone marrow transplant

Answer 7

• treat diseases of blood (eg. sickle-cell anaemia) & immune system
• used to restore patient’s blood system after treatment for specific types of cancer –> patients bone-marrow cells extracted prior to treatment & stored

Question 8

(research/medicine) drug research

Answer 8

• stem cells can be made to develop into particular types of human tissue
• new drugs can be tested 1st on these tissues

Question 9

(research/medicine) developmental biology

Answer 9

• study how these cells develop to make particular cell types & can learn how each cell type functions/see what goes wrong when they’re diseased
• trying to find out if they can extend capacity that embryos have for growth/tissue repair into later life

Question 10

(repair of damaged tissues/replacement of lost tissues) how have stem cells been using to treat mice with type 1 diabetes

Answer 10

• programming iPS cells to become pancreatic beta cells
• research is underway to develop such treatment for humans

Question 11

(repair of damaged tissues/replacement of lost tissues) what can bone-marrow stem cells be made to develop into

Answer 11

= liver cells (hepatocytes)
- could be used to treat liver disease

Question 12

(repair of damaged tissues/replacement of lost tissues) what could stem cells directed to become nerve tissue be used for

Answer 12

• treat alzheimer/parkinson diseases
• repair spinal-cord injuries

Question 13

(repair of damaged tissues/replacement of lost tissues) describe regenerative medicine

Answer 13

• stem cells could be used to populate a bioscaffold of an organ & then directed to develop/grow into specific organs for transplanting
• if patient’s cells are obtained, reprogrammed to become iPS cells & used to make such an organ = no need for immunosuppressant drugs

Question 14

(repair of damaged tissues/replacement of lost tissues) which conditions could stem stells treat

Answer 14

including:
- arthritis
- strokes
- burns
- vision/hearing loss
- duchenne muscular dystrophy
- heart disease