Scientists investigated cells taken at different stages of development. Each cell was cultured under conditions in which it could divide.
| Sample | Source of the cell | Result after culture |
|---|---|---|
| A | a very early chicken embryo, after the fertilised egg had divided a few times | nerve cells, muscle cells and liver cells formed |
| B | an area beginning to form the liver in an older chicken embryo | only liver cells formed |
| C | the liver of an adult chicken | only liver cells formed |
| D | a leaf of an adult tomato plant | root hair cells, xylem cells and leaf cells formed, and a complete plant developed |
Explain how cell differentiation accounts for the results for samples A, B, C and D.
Include why the change shown between samples A and B is important in the development of the chicken.
282 exam-style questions on AQA GCSE Biology 1.1 Cell structure, covering 1.1.1 Eukaryotes and prokaryotes, 1.1.2 Animal and plant cells, 1.1.3 Cell specialisation, 1.1.4 Cell differentiation, 1.1.5 Microscopy, and 1.1.6 Culturing microorganisms. Each one has a worked solution and a mark scheme showing where the marks go.