(Bio) Stem Cells P&A

What is a stem cell?

An undifferentiated cell that can divide to produce more cells of the same type and can differentiate to form other types of cells

What is differentiation?

The process by which cells change and become specialised

What are embryonic stem cells?

Stem cells found in an early embryo that can differentiate into any type of body cell

Where are adult stem cells found in the human body?

In bone marrow

What is the difference between embryonic and adult stem cells?

Embryonic stem cells can differentiate into any type of cell, whereas adult stem cells can only differentiate into certain types of cell

What types of cells do bone marrow stem cells differentiate into?

Red blood cells, white blood cells and platelets

What is leukaemia?

A cancer of the bone marrow

How is a bone marrow transplant used to treat leukaemia?

The patient's existing bone marrow is destroyed using radiation ,then donor bone marrow is transplanted so the stem cells can divide and form new bone marrow and blood cells

Give two problems with bone marrow transplants

The donor must be compatible with the patient otherwise white blood cells could attack the patient's body, and a risk of viruses being transferred

What is therapeutic cloning?

A process where an embryo is produced with the same genes as the patient

Why are stem cells from therapeutic cloning not rejected by the patient's immune system?

Because the embryo has the same genes as the patient

Give two medical conditions that therapeutic cloning could potentially treat

Diabetes and paralysis

Why do some people object to therapeutic cloning?

Some people have ethical or religious objections to the procedure

Where are stem cells found in plants?

In meristem tissue

What is special about plant meristem stem cells?

They can differentiate into any type of plant tissue at any point in the plant's life

Give two uses of cloning plants using meristem tissue

To clone rare plants to prevent extinction and to produce disease resistant crop plants