Grade-6-Science-Olympiad: Environmental Science Magazine - Free Printable

Let’s go through each question one by one and think carefully about the right answer.

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Question (1): What is the carbon cycle?

We know that carbon doesn’t just disappear — it moves around in nature. Plants take in carbon dioxide from the air, animals eat plants, and when things die or burn, carbon goes back into the air or soil. So it’s a *cycle* — meaning it keeps going round and round between living things and the atmosphere.

Look at the options:

- (A) says carbon is “consumed” — but that’s only part of it. It doesn’t mention recycling.
- (B) says carbon is “recycled between the atmosphere and living things” — YES! That’s exactly what the carbon cycle is.
- (C) and (D) talk about converting carbon to CO₂ or vice versa — those are steps in the cycle, not the whole thing.

✔ So the best answer is (B).

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Question (2): Which of the following is not a Carbon product in an ecosystem?

“Carbon product” means something made of carbon or containing carbon that exists in nature as part of the ecosystem.

Let’s check each option:

- (A) Carbon Dioxide — yes, it has carbon (CO₂).
- (B) Water — H₂O. No carbon here! Just hydrogen and oxygen.
- (C) Fossil fuel — like coal or oil — definitely full of carbon.
- (D) Plant — plants are made of carbon-based molecules (like sugars, cellulose).

So water does NOT contain carbon. It’s not a carbon product.

✔ Answer is (B).

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Question (3): What happens when fossil fuels such as coal or oil are burned?

When you burn anything with carbon (like wood, coal, gasoline), it reacts with oxygen and makes carbon dioxide. That’s basic chemistry.

Check the options:

- (A) Nitrogen? Not really produced from burning fossil fuels — unless it’s very hot, but that’s not the main point.
- (B) Oxygen? No — we use up oxygen when we burn things.
- (C) Carbon Dioxide is produced and released — YES! That’s correct.
- (D) Carbon? We don’t release pure carbon — it becomes CO₂ gas.

✔ Correct answer is (C).

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Question (4): What is photosynthesis?

Photosynthesis is how plants make their own food. They use sunlight, water, and carbon dioxide to make sugar (glucose). The carbon comes from CO₂ in the air.

Look at the choices:

- (A) Says plant leaves take carbon from CO₂ to make sugar, starch, protein — YES! That’s accurate.
- (B) Says they take *oxygen* from CO₂ — no, they take the *carbon*, and release oxygen.
- (C) and (D) talk about decomposers making or destroying CO₂ — that’s respiration or decay, not photosynthesis.

✔ So the right answer is (A).

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Final Answer:
(1) B
(2) B
(3) C
(4) A