# A student observes two types of cells under an electron microscope: a mesophyll cell from a plant leaf and a bacterium. Explain why the bacterium would not show membrane-bound organelles when viewed at the same magnification as the mesophyll cell.

> OCR A-Level Biology A (H420) — 2.1 Cell structure · Explain · 4 marks

> Mesophyll cells are found in plant leaves and are the primary site of photosynthesis. Bacteria are unicellular organisms that can be found in a wide range of environments, including soil and living tissues.

## Mark scheme (4 marks)

1. Bacteria are prokaryotic organisms
2. Prokaryotic cells lack membrane-bound organelles
3. The mesophyll cell is eukaryotic and does possess membrane-bound organelles
4. Correct contrast linking the presence or absence of a nuclear envelope or named membrane-bound organelle to cell type

## Key terms

- [electron microscope](https://www.gradenine.co.uk/glossary/electron-microscope)
- [membrane-bound organelles](https://www.gradenine.co.uk/glossary/membrane-bound-organelles)
- [mesophyll cell](https://www.gradenine.co.uk/glossary/mesophyll-cell)
- [magnification](https://www.gradenine.co.uk/glossary/magnification)

## Related

- [Revision notes for OCR A-Level Biology A (H420)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-observes-two-types-of-22e714a5) · Published by Druglandscape Ltd.