A scientist looked at samples of three human tissues under a microscope. For each tissue she counted how many cells out of every 1000 cells were dividing.
Table: The number of dividing cells per 1000 cells in three human tissues
| Tissue | Number of dividing cells per 1000 cells |
|---|---|
| lining of the small intestine | 145 |
| liver | 12 |
| heart muscle | 3 |
Use the table. Calculate the percentage of cells that were dividing in the lining of the small intestine.
Use the table. Calculate the percentage of cells in the liver that were not dividing.
Use the table. Calculate how many times as many dividing cells per 1000 cells there are in the liver compared with heart muscle.
The cells lining the small intestine are damaged and lost as food moves through the intestine.
Suggest why the lining of the small intestine has many more dividing cells than heart muscle.
The scientist concluded: 'The table shows that cells in heart muscle can differentiate into other types of cell.'
Explain why the data in the table do not support this conclusion.
139 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.