A student wanted to find the number of cells in a thin layer of onion epidermis.
The student counted the cells in five different fields of view using a light microscope.
The Table shows the student's results.
Table
| Field of view | Number of cells |
|---|---|
| 1 | 42 |
| 2 | 38 |
| 3 | 45 |
| 4 | 40 |
| 5 | 35 |
Give one reason why the student estimated the number of cells rather than counting every cell in the onion epidermis.
Calculate the mean number of cells in one field of view.
The whole layer of onion epidermis has the same area as 150 fields of view.
Estimate the number of cells in the whole layer of onion epidermis.
Suggest one way the student could make the estimate more accurate.
48 exam-style questions on Edexcel GCSE Biology 1.2 Number, size and scale, covering 1.2.1 Number, size and scale with estimations and 1.2.2 Quantitative units in relation to cells. Each one has a worked solution and a mark scheme showing where the marks go.