Stem cells 2.6.9

Question 1

What is a stem cell?

Answer 1

A cell that has the ability to develop into different types of cells (unspecialised), and is able to express all of its genes

Question 2

What is a totipotent cell?

Answer 2

Forms after a zygote has undergone 3 complete cell cycles. And it consists of eight identical cells which are totipotent.
These cells can give rise to any specialised cells which make up the adult human body.

Question 3

What is a pluripotent cell?

Answer 3

They are present in the early embryo and re the origin of the different types of tissues within the organism.
They are able to give rise to most types of specialised cell but not all.

Question 4

Where are stem cells found?

Answer 4

• Embryonic stem cells -> blastocyst (very early embryo)
• Tissue stem cells -> foetus, baby, and throughout life.
• Umbilical cord
• iPS cells, developed in the lab by reprogramming differentiated cells

Question 5

What is a multipotent cell?

Answer 5

Cells found in adults which still have the ability to differentiate and give rise to a variety of cell types.
- E.g. multipotent stem cells in bone marrow develop into different sorts of blood cell.

Question 6

What are bone marrow transplants used for?

Answer 6

• Treat leukaemia
• Restore patients blood systems after treatment for specific types of cancer
• Diseases of the immune system

Question 7

What can stem cells be used for?

Answer 7

• Bone marrow transplants
• Developmental biology
• Drug research
• Nerve tissue produced to treat Parkinsons
• Skin cell production to treat patients with burns

Question 8

What are the ethical concerns associated with stem cells?

Answer 8

The main concern is about the status of the embryos harvested for stem cells, as some people regard the embryo as having full human status.