# Explain why totipotency in plant cells makes it possible to produce large numbers of genetically identical plants from a single parent plant using tissue culture techniques.

> OCR A-Level Biology A (H420) — 6.4 Cloning and biotechnology · Explain · 4 marks

> Commercial plant growers use micropropagation to produce thousands of identical copies of high-value ornamental plants. Small pieces of tissue called explants are taken from a parent plant and cultured on nutrient agar containing specific plant growth regulators.

## Mark scheme (4 marks)

1. Totipotency means that each plant cell retains the full genetic information (genome) of the organism
2. Totipotent cells are able to differentiate into any cell type and develop into a complete organism
3. Explant cells are stimulated by plant growth regulators (auxins/cytokinins) to dedifferentiate and form a callus
4. Callus cells can be subdivided and redifferentiated into whole plants, all sharing identical genetic information to the parent, producing clones at large scale

## Key terms

- [totipotency](https://www.gradenine.co.uk/glossary/totipotency)
- [tissue culture](https://www.gradenine.co.uk/glossary/tissue-culture)

## 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)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-totipotency-in-plant-cells-09b2d263) · Published by Druglandscape Ltd.