# Explain how carbon moves from atmospheric carbon dioxide into the organic molecules of a primary consumer.

> IB DP Biology Standard Level (2023 syllabus) — C4.2 Transfers of energy and matter · Explain · 4 marks

## Mark scheme (4 marks)

1. Plants (producers) absorb/fix atmospheric CO₂ during photosynthesis
2. Carbon is incorporated into organic/carbon-containing molecules (e.g. glucose/sugars/carbohydrates) in the producer
3. The primary consumer obtains carbon by feeding on / consuming the producer
4. Carbon-containing molecules from the producer are digested and assimilated into the consumer's own organic molecules / used in biosynthesis

## Key terms

- [organic molecules](https://www.gradenine.co.uk/glossary/organic-molecules)
- [primary consumer](https://www.gradenine.co.uk/glossary/primary-consumer)

## Related

- [Revision notes for IB DP Biology Standard Level (2023 syllabus)](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/explain-how-carbon-moves-from-atmospheric-1de1ab75) · Published by Druglandscape Ltd.