GCSE Biology - B3 (OCR 21st Century Science)

How do nitrates in the soil return to nitrogen in the air?

In its simplest terms, what does natural selection mean?

Explain why classification is useful.

How is carbon dioxide returned to the atmosphere?

How does energy leave the food chain?

Which scientist thought that organisms adapted themselves and these are passed onto offspring?

Suppose there's an increase in wild cats. Why will this have a neutral effect on jackals?

Find the percentage efficiency. You may use a calculator.

Bags made of paper and card are biodegradable. What does biodegradable mean?

High levels of nitrates in a river could indicate what?

What are the disadvantages with using biodegradable materials?

Which of these statements are true about how evolution works?

How can mutations be caused?

How can isolation lead to the two groups involved turning into a new species?

What process 'powers' the carbon cycle/the main way that CO₂ is removed from the air?

The theory of evolution works due to what process?

Explain why organisms in the same species may look different.

How does nitrogen get from the air into the soil?

Why might humans use selective breeding?

In an ecosystem, why is most of the energy from the sun not used in the producer?

What provides evidence for evolution?

How can packaging be made more sustainable?

The higher the world's population...

What are mayfly nymphs sensitive to?

Why is biodiversity an advantage?

When microorganisms decompose waste and urea, what do they turn it into?

Which organism in the food chain will receive the least energy?

What is meant by a species?

If the number of lichen in an area is low, what might this indicate?

What might cause a species to go extinct?

An ecosystem with a large biodiversity would have what features?

Why is selective breeding different to natural selection?

What is it called when humans select which organisms breed together?

Which key term describes the idea that all organisms depend on others for their survival?

How does natural selection work?