Stem Cells and Totipotency

Question 1

Why do cells specialize?

Answer 1

To be best suited to carry out its specific function

Question 2

Give an example of totipotent cells

Answer 2

The zygote (fertilised egg)

Question 3

How are zygote’s totipotent?

Answer 3

As they can give rise to any body cell or non body cell like the placenta.

Question 4

Name two ways to prevent genes from expressing themselves?

Answer 4

1. Preventing transcription and so preventing formation of mRNA
2. Preventing translation

Question 5

What is an embryonic stem cell?

Answer 5

Come from embryos in their early stages of development. They can differentiate into any type of cell in the initial stages of development.

Question 6

What is an umbilical cord blood stem cell?

Answer 6

Derived from umbilical cord blood, are similar to adult stem cells

Question 7

What are placental stem cells?

Answer 7

Found in the placenta and develop into specific types of cell.

Question 8

What are adult stem cells?

Answer 8

Found in body tissues of fetus through to adult. they are specific to a particular tissue or organ within which they produce the cells maintain and repair tissues.

Question 9

Totipotent stem cells?

Answer 9

Come from embryos in their early stages of development. They can differentiate into any type of cell.

Question 10

Pluripotent stem cells?

Answer 10

Found in embryos can differentiate into almost any type of cell. e.g. embryonic stem cells and fetal stem cells

Question 11

Multipotent stem cells?

Answer 11

Can differentiate into limited number of specialized cells, examples include bone marrow stem cells that can divide into all types of blood cell.

Question 12

Unipotent stem cells?

Answer 12

can only differentiate into one single type of cell. they are derived from multipotent stem cells and are made in adult tissue.

Question 13

What are induced pluripotent stem cells?

Answer 13

Type of pluripotent stem cell that is produced from unipotent stem cells. The unipotent stem cell can be almost any body cell.

Question 14

How are induced pluripotent cells stem cells made?

Answer 14

Body cells are genetically altered in a lab to make them have the characteristics of an embryonic stem cell. This involves inducing genes and transcriptional factors within the cell to express themselves.

Question 15

Give proof adult cells posses all genetic information.

Answer 15

1. All derived from the zygote

2. That adult cells can be induced to form pluripotent stem cells found in embryo.

Question 16

Benefits of IPS cells?

Answer 16

1. capable of self renewal meaning infinite supply and can replace embryonic stem cells in stem cell research negating ethical issues

Question 17

How can pluripotent cells treat human disorders?

Answer 17

1. can be used to regrow damaged tissue e.g.burns
2. Treating neuro-degenerative diseases like Parkinson
3. Treat muscular dystrophy
4. bone cells like osteoporosis

Question 18

List of stem cell treatable diseases (remember 2-3)

Answer 18

heart muscle cells - heart attack damage
skeletal muscle cells - muscular dystrophy
bone cells - osteoporosis

Question 19

Example of unipotent stem cell ?

Answer 19

cardiomyocyte