L-26

Question 1

What are the steps of embryo development?

Answer 1

• begins as a small number of naive totipotent cells
• cells go through polarisation and compaction
• the inner, apolar, cells are cut off
• develops into a blastocyst composed of the trophectoderm and the ICM

Question 2

What does totipotent mean?

Answer 2

To have total potential

Question 3

What is the trophectoderm?

Answer 3

The outside cells of the blastocyst (formerly polar)

Question 4

What is the ICM?

Answer 4

Inside cells of the blastocyst (formally apolar)

Question 5

What is a terminally differentiated cell?

Answer 5

cells that can only give rise to the same type of cell as itself

Question 6

Are human embryonic stem cells totipotent, multi potent, pluripotent, or terminally differentiated?

Answer 6

Pluripotent

Question 7

What does pluripotent mean?

Answer 7

They can develop into any of the 200 or so types of cell in our bodies, given the right conditions

Question 8

Are induced pluripotent stem cells totipotent, multi potent, pluripotent, or terminally differentiated?

Answer 8

Pluripotent

Question 9

Are Adult stem cells totipotent, multi potent, pluripotent, or terminally differentiated?

Answer 9

Multipotent

Question 10

Are umbilical cord stem cells totipotent, multi potent, pluripotent, or terminally differentiated?

Answer 10

Multi potent

Question 11

Where are embryonic stem cells harvested from?

Answer 11

From the inner cell mass (future embryo) off mammalian blastocyst embryos

Question 12

What is the relationship genetically of the embryonic stem cells to the embryo donor?

Answer 12

Genetically identical

Question 13

How are induced pluripotent stem cells made?

Answer 13

Made by reprogramming adult skin cells

Question 14

What is the relationship of induced pluripotent stem cells to the adult skin cells?

Answer 14

Genetically identical

Question 15

Are adult stem cells differentiated or undifferentiated?

Answer 15

Undifferentiated

Question 16

What can adult stem cells give rise to?

Answer 16

• stem cells

- cells which will do on to differentiate into one or more types of functional tissue cells

Question 17

Why is cord blood banking common practise in some countries?

Answer 17

To preserve less restricted and more immature multi potent stem cells that can be used to treat potentially future leukaemias and other blood diseases

Question 18

What are renewal tissues?

Answer 18

Blood and skin which need constant renewing

Question 19

What stem cell types are found in the bone marrow and can be used for transplants?

Answer 19

• blood stem cells

- haematopoietic stem cells

Question 20

What is the difference in cell potential between a fertilised egg and embryonic stem cells and adult stem cells

Answer 20

• fertilised egg is totipotent
• embryonic stem cells are pluripotent
• adult stem cells are multipotent

Question 21

What is used to persuade stem cells to develop into different kinds of differentiated cells?

Answer 21

Different culture conditions

Question 22

How can gene therapy be used to correct single gene disorders?

Answer 22

Normal allele can be inserted into the cells of the affected tissue. A virus can deliver genetic material into human cells

Question 23

What is B- thalassemia caused by?

Answer 23

A defective HBB gene, which codes for the beta-globin protein which is the part of haeomoglobin found in red blood cells

Question 24

What are the symptoms of B-thalassemia?

Answer 24

• anemia
• poor oxygen transport
• blood clots

Question 25

How has gene therapy been used to successfully treat B-thallasemia?

Answer 25

Blood stem cells found in bone marrow were extracted and engineered to add a “good” copy of the HBB gene, once the cells are replaced, they pass a new copy onto all newly made red blood cells

Question 26

What can pluripotent stem cells be made from?

Answer 26

- skin or blood cells from a patient (genetically identical) - skin or blood cells from a matched donor - embryonic stem cells

Question 27

How does regenerative medicine work?

Answer 27

- Stem cells can be encouraged to differentiate into specific cell types such as neurons, or retinal cells - these cells can be transplanted int patients

Question 28

What is an example of regenerative medicine?

Answer 28

Retinal pigment epithelial cell grafts, to reverse macular degeneration

Question 29

What proportion of people over 50 are affected by macular degeneration?

Answer 29

1/7

Question 30

What are the symptoms of macular degeneration?

Answer 30

- blurring, distortion, loss of vision

Question 31

What is the cause of macular degeneration?

Answer 31

Damage to retinal pigmented epithelium cells