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What is the carbon cycle?
The movement of carbon between the air, living things, decomposers, and fossil fuels.
How do plants get carbon?
By taking in carbon dioxide from the air for photosynthesis.
Why do farmers add fertilisers to soil?
To provide minerals for better growth and higher yield.
In what form do plants store extra carbohydrates?
Starch.
Why do plants still release carbon dioxide at night?
They respire but cannot photosynthesise without sunlight.
Where does photosynthesis take place in a cell?
In the chloroplasts.
What happens to a plant if it lacks magnesium?
Leaves turn yellow and growth is poor because less photosynthesis happens.
What are stomata?
Tiny holes in leaves that allow gases to diffuse in and out.
How do decomposers get carbon?
By breaking down waste and dead organisms.
Write the word equation for photosynthesis.
Water + Carbon dioxide → Glucose + Oxygen
What happens to dead organisms in places with no oxygen?
They can turn into fossil fuels over millions of years.
Why are leaves thin?
So sunlight can penetrate easily and gases can diffuse quickly.
How do animals get carbon compounds?
By eating plants or other animals.
Which mineral is needed to make chlorophyll?
Magnesium.
How can you test if a leaf has been photosynthesising?
Test the leaf for starch.
What are the two products of photosynthesis?
Glucose and oxygen.
What pigment absorbs light for photosynthesis?
Chlorophyll.
Why are fossil fuels non-renewable?
They take millions of years to form and are used faster than replaced.
What three things do plants need for photosynthesis?
Water, carbon dioxide, and sunlight.
How is carbon returned to the air by living things?
Through respiration.
Why do plants need proteins?
To make new cells for growth.
What is the word equation for respiration?
Glucose + Oxygen → Carbon dioxide + Water.
Why is photosynthesis important for animals as well as plants?
It provides energy (as carbohydrates) and oxygen needed for respiration.
Name one human activity that adds extra carbon dioxide to the atmosphere.
Burning fossil fuels (combustion).
Which mineral is needed for making proteins?
Nitrate.