# A student observes two types of cells under a microscope. One cell has a nucleus, mitochondria, and a cell wall made of cellulose. The other cell has no nucleus, no mitochondria, and a cell wall made of a different material. Explain how these observations allow the student to identify which cell is a plant cell and which is a bacterial cell, and describe one key difference in how genetic material is stored in each cell type.

> Pearson Edexcel A-Level Biology A (9BI0) — Topic 2 Cells, Viruses and Reproduction · Explain · 5 marks

> The student notes that one cell is approximately 100 µm in diameter and the other is approximately 2 µm in diameter.

## Mark scheme (5 marks)

1. The cell with a nucleus, mitochondria, and cellulose cell wall is the plant cell
2. The cell with no nucleus and no mitochondria is the bacterial cell, as it is a prokaryotic cell
3. In the plant cell, the genetic material (DNA) is stored inside the nucleus, enclosed by a nuclear membrane
4. In the bacterial cell, the genetic material is not enclosed in a nucleus but floats freely in the cytoplasm
5. The size difference supports the identification, as bacterial cells are much smaller than plant cells (prokaryotic cells are smaller than eukaryotic cells)

## Key terms

- [nucleus](https://www.gradenine.co.uk/glossary/nucleus)
- [genetic material](https://www.gradenine.co.uk/glossary/genetic-material)

## Related

- [Revision notes for Pearson Edexcel A-Level Biology A (9BI0)](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)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-observes-two-types-of-a5379287) · Published by Druglandscape Ltd.