Differentiation and Stem Cells
An unspecialised cell switches on part of its genes and becomes a cell with a job. Compares embryonic, adult and plant meristem stem cells, with the medical uses and the objections that come with them.
What a learner can do afterwards
- Explains what differentiation changes inside a cell, given that every cell holds the same genes.
- Compares what embryonic and adult stem cells can turn into.
- Gives one medical use of stem cells and one objection people raise to it.
1 · Read
You began as one cell holding every gene needed to build you. Differentiation is how its daughters take on jobs: each keeps the full gene set but switches on only the genes its job needs. A muscle cell reads the contracting chapters, a nerve cell reads the signalling ones.
Transcription factors are the switches. These proteins bind near DNA and turn genes on or off in each cell. That is why two cells with the same book can read different chapters and end up looking nothing alike.
Cells without a job yet are stem cells. Embryonic stem cells are pluripotent and can turn into almost any cell type. Adult stem cells, hiding in places like bone marrow, are multipotent and replace only their neighbours. Plants keep growing all their lives using meristem cells at root and shoot tips.
Stem cells can treat disease, for example by replacing damaged blood cells, but their use raises objections, especially around embryos. Give one medical use and one objection, and say which cell type each point is about.
Every cell holds the same genes, switching turns some on, and stem cells keep their options open.
2 · Watch
Take it off screen
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.