These seven original questions follow the four lessons in environmental sustainability. Try each before opening the answer.
Questions
Q1. Order these into a chain: (a) fish numbers fall, (b) factory waste enters a stream, (c) oxygen in the water drops.
Answer
The order is (b), (c), (a): waste enters, oxygen drops, so fish numbers fall. Each step is the effect of the one before.
Q2. A student writes “fish die, so oxygen falls” for a polluted pond. Is the order correct?
Answer
No. The order is reversed. Low oxygen came first and caused the fish to die, so the statement should read “oxygen falls, so fish die”.
Q3. Nest counts rise from 25 to 35. Calculate the percentage change.
Answer
(35 − 25) ÷ 25 × 100 = 40% increase.
Q4. 400 eggs are laid and 300 hatch. Find the hatching success and state what it does not show.
Answer
300 ÷ 400 × 100 = 75%. It does not show how many young survive to adulthood, or the total population.
Q5. Option X costs little but takes years to work. Option Y is fast but costly. Write a two-sentence evaluation for a question that stresses speed.
Answer
“Option Y is better here because it works fast, which matches the priority. However, it is costly, so the project would need enough funds.” Any choice is acceptable if it follows the stated priority and names a limit.
Q6. A student writes “the new law proves the river is clean.” Give two reasons the claim is unsupported.
Answer
“Proves” is too strong for the evidence, and a law does not show cleanness without water measurements. The claim also ignores the scope: one site or one year may not show the state of the whole river.
Q7. Rewrite Q6 as a supported claim if data shows dissolved oxygen rose from 5 to 7 mg per litre at one site.
Answer
“Dissolved oxygen at one site rose from 5 to 7 mg per litre after the law, which suggests water quality may be improving, but more sites and more time are needed to be sure.”
If you got these wrong
Q1 and Q2 point to causes and effects. Q3 and Q4 need interpreting conservation data.
Q5 links to evaluating a management action. Q6 and Q7 use avoiding unsupported claims.
Use the timed practice builder to repeat questions and the mistake log to record slips. If you want a teacher to read your written answers, see online one-to-one Biology tuition.