---
title: "Quick check: the whole carbon cycle"
subtitle: "Year 9 Earth and space · The carbon cycle · Lesson 5"
---

# Quick check: the whole carbon cycle

**Name:** {{field-24}} **Date:** {{field-15}} **Class:** {{field-15}}

> **Key question:** Carbon has been moving between air, living things, water and rock for billions of years. What have we changed?


:::teacher-note

**In one sentence:** A self-test on the whole carbon cycle: flows between spheres, what drives each, and the effect of combustion (AC9S9U03, node 5, taught in class).

**Students should be able to say:** I can name the main carbon flows between spheres. I can sort flows as biological, geological or human-driven. I can explain how burning fossil fuels changed the balance.

**Width:** the unmarked parts are the floor every student does (Engage, Explore, Explain, Evaluate). Typical and Wider sections add contexts, not difficulty. Students work in the online tutorial alongside this sheet.

:::


## The whole cycle


:::keep-together

### Between spheres

**Which flow moves carbon from the atmosphere into the biosphere?**

☐ Decomposition

☐ Photosynthesis

☐ Combustion

☐ Respiration

:::


:::teacher-note

**Answer:** Photosynthesis

Plants take carbon dioxide from the air and build it into sugars. Respiration, combustion and decomposition move carbon the other way.

:::


:::keep-together

### Where from, where to

**Match each flow to where it moves carbon.**

A. Geosphere to atmosphere

B. Atmosphere to hydrosphere

C. Atmosphere to biosphere

D. Biosphere to atmosphere

{{columns 60% 40%}}

{{rows 1}}

| Part | Letter |
|---|---|
| `Photosynthesis` | |
| `Respiration by animals` | |
| `Burning coal` | |
| `The ocean dissolving carbon dioxide` | |

:::


:::teacher-note

**Answer:** Photosynthesis → C. Atmosphere to biosphere; Respiration by animals → D. Biosphere to atmosphere; Burning coal → A. Geosphere to atmosphere; The ocean dissolving carbon dioxide → B. Atmosphere to hydrosphere

:::


:::keep-together

### What drives the flow?

**Is the flow biological, geological or human-driven?**

Groups: Biological, Geological, Human-driven

- Photosynthesis: {{field-15}}
- Respiration: {{field-15}}
- Decomposition: {{field-15}}
- A volcano releasing carbon dioxide: {{field-15}}
- Burning petrol in cars: {{field-15}}
- Clearing and burning a forest: {{field-15}}

:::


:::teacher-note

**Answer:** Photosynthesis → Biological; Respiration → Biological; Decomposition → Biological; A volcano releasing carbon dioxide → Geological; Burning petrol in cars → Human-driven; Clearing and burning a forest → Human-driven

:::


:::keep-together

### The human change

**Why has burning fossil fuels changed the carbon cycle's balance?**

☐ It moves carbon that was stored for millions of years into the air in a few centuries, faster than natural processes remove it

☐ It has no effect, because natural flows are much bigger

☐ It makes plants stop photosynthesising

☐ It destroys carbon

:::


:::teacher-note

**Answer:** It moves carbon that was stored for millions of years into the air in a few centuries, faster than natural processes remove it

The natural flows nearly balance each other. The extra flow from fossil fuels is not balanced, so carbon builds up in the air.

:::


## Exit ticket

:::keep-together

**Name one biological, one geological and one human-driven carbon flow.**

{{lines-3}}

:::


:::teacher-note

**Answer:** For example photosynthesis, a volcanic eruption, burning petrol.

:::