Stem Cells

This lesson covers stem cells — what they are, where they are found, how they can be used, and the ethical issues surrounding their use. This is essential content for Edexcel GCSE Biology (1BI0) Topic 2: Cells and Control. Stem cell biology is a rapidly developing field with enormous potential for treating diseases.

---

What Are Stem Cells?

A stem cell is an unspecialised cell that can:

1. Divide by mitosis to produce more stem cells (self-renewal).
2. Differentiate into specialised cell types.

This combination of properties makes stem cells uniquely valuable. Most body cells are already specialised and cannot change into different types, but stem cells retain this ability.

---

Types of Stem Cell

There are several types of stem cell, each with different properties:

Embryonic Stem Cells

• Found in early-stage embryos (blastocysts, about 5 days after fertilisation).
• They are pluripotent — they can differentiate into almost any cell type in the body.
• This makes them extremely useful for medical research and potential treatments.
• Embryonic stem cells are obtained from unused embryos from IVF treatment (with consent).

Adult Stem Cells