Cellular Differentiation

Question 1

What is a totipotent cell?

Answer 1

An isolated cell that is able to produce a fertile adult individual

Question 2

What is a pluripotent cell?

Answer 2

Embryonic stem cells can give rise to all cell types expect trophectoderm

Question 3

How does a cells fate change as it becomes terminally differentiated?

Answer 3

A cells fate is progressively limited until it becomes terminally differentiated and can only give rise to same type of cell
Exception : stem cells, germ cells

Question 4

At embryonic cell stage what could the cell become?

Answer 4

At this stage in development the cell could become any type of differentiated cell

Question 5

What does it mean when cells are off?

Answer 5

Cells not being transcribed in mRNA
Not making RNA or protein

Question 6

How does a cells fate become determined?

Answer 6

Certain control genes which code for transcription factors become activated when cell is turned on

Question 7

What does MyoD protein do?

Answer 7

It is a transcription factor that can turn genes on or off

Question 8

What does it mean when a cell is terminally differentiated?

Answer 8

It will stop diving and can play a functional role in the organism

Question 9

What is genomic equivalence?

Answer 9

Differentiated cells contain all the DNA required to build an entire new organism

Question 10

What are embryonic stem cells? (ESC’s)

Answer 10

These are cells that are harvested from the inner cell mass of mammalian blastocyst embryos
Human embryonic stem cells are pluripotent (can develop into ~ 200 types)
Cells derived from ESC’s are genetically identical to embryo donor

Question 11

What are adult tissue stem cells?

Answer 11

Stem cells that can divide without limit
Undifferentiated multipotent cells
They can divide to give rise to both stem cells and cells which will go onto differentiate into one or more types of functional tissue cells

Question 12

What are umbilical cord stem cells?

Answer 12

Stem cells from blood isolated from umbilical cord of newborn babies are kept frozen
Stem cells are multipotent as they are immature blood stem cells, they are less restricted than blood stem cells from adults
Can be used to treat leukaemia and other blood diseases

Question 13

What is renewal tissues in relation to adult stem cells?

Answer 13

Stem cells are important for tissues such as blood and skin which need constant renewing

Question 14

What is another name for blood stem cells, where and they found and what can they be used for?

Answer 14

Haematopoietic stem cells
Found in bone marrow
Can be used for transplants

Question 15

Is a fertilised egg totipotent, pluripotent or multipotent?

Answer 15

Totipotent
Able to give rise to all cell types via cell division

Question 16

Are embryonic stem cells totipotent, pluripotent or multipotent?

Answer 16

Pluripotent
Can become all/any cells of the body

Question 17

Are adult stem cells e.g. bone marrow totipotent, pluripotent or multipotent?

Answer 17

Multipotent
Usually can only give rise to one or a few cell types

Question 18

How can you persuade stem cells to develop different kinds of differentiated cells?

Answer 18

Using different culture conditions

Question 19

What is integrative gene therapy?

Answer 19

Integrative gene therapy is based on the idea that it may be possible to alter the genetic code of an individuals cell through correcting single gene disorders by inserting a normal allele into affected tissue

Question 20

What is regenerative medicine?

Answer 20

Based on the idea that pluripotent stem cells can be used to repair or replace damaged organs or tissues. Made from skin cells or bloods cells from a patient, donor or embryo that can be encouraged to differentiate into specific cell types

Question 21

What are Induced Pluripotent Stem (iPS) cells

Answer 21

iPS cells are made by reprogramming adult skin cells
iPS cells can be made from anyone and are genetically identical to the source skin cells. They are also pluripotent meaning they can generate any cell type