What is a stem cell?
An undifferentiated cell that can divide and become specialised.
What is differentiation?
The process where a stem cell becomes a specialised cell.
What are the two main types of stem cells in humans?
Embryonic stem cells and adult stem cells.
What are embryonic stem cells?
Stem cells from early embryos that can become any type of cell (pluripotent).
What are adult stem cells?
Stem cells found in tissues like bone marrow; can form a limited range of cells (multipotent).
What does pluripotent mean?
Able to become almost any type of cell.
What does multipotent mean?
Able to become only certain types of cells.
What are meristem cells?
Plant stem cells found in growing regions (shoots and roots).
What can meristem cells differentiate into?
Any type of plant cell, including xylem and phloem.
What is the main benefit of embryonic stem cells?
They can treat a wide variety of illnesses because they can become any cell type.
Why are embryonic stem cells useful in medicine?
They can replace damaged or diseased cells in conditions like paralysis or diabetes.
What is a major downside of embryonic stem cells?
Extraction can harm or destroy the embryo, causing ethical concerns.
Why is embryonic stem cell extraction painless?
Embryos do not have a nervous system, so they cannot feel pain.
Why are embryonic stem cells considered unreliable?
Treatments are relatively untested and may behave unpredictably.
What is a tumour risk in stem cell therapy?
Embryonic stem cells may divide uncontrollably and form tumours.
Benefit of adult stem cells
No ethical issues; using a patient’s own cells reduces risk of rejection.
Downside of adult stem cells
They can only form a limited range of cells (multipotent).
Why can extracting adult stem cells be painful?
Bone marrow extraction can be uncomfortable or painful.
How can pain during extraction affect donation?
It may discourage potential donors from volunteering.
What is a risk of adult stem cell extraction?
Infection or bleeding during the procedure.
Why are adult stem cells harder to use in medicine?
They divide slowly and are harder to grow in labs.
Why might adult stem cell treatments fail?
The cells may not divide enough or may not specialise correctly.
What is therapeutic cloning?
Creating an embryo with the patient’s DNA to produce matching stem cells.
Benefit of therapeutic cloning
No risk of rejection because the cells are genetically identical to the patient.
