Question 1
What is the principal source of energy input to biological systems?
- Chemical energy in glucose
- Heat from the soil
- Light energy from the Sun
- Energy released by decomposers
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Answer: C (1)
Question 2
In a food chain, what do the arrows show?
- The direction in which animals move
- The transfer of energy from one organism to the next
- The number of organisms at each level
- The organisms that are harmful to others
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Answer: B (1)
Question 3
Describe the flow of energy through living organisms, starting with light energy from the Sun.
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- light energy is transferred to chemical energy in producers / plants by photosynthesis (1)
- chemical energy passes to consumers / along the food chain when organisms feed (1)
- energy is eventually transferred to the environment / lost as heat (1) allow lost through respiration
Question 4
A food chain is: lettuce → snail → thrush → sparrowhawk (a) State the producer in this food chain. [1] (b) State the organism that is the secondary consumer. [1] (c) Name the organism that gets its energy directly from the thrush. [1] (d) State what the arrow between the lettuce and the snail represents. [1]
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- (a) lettuce (1)
- (b) thrush (1)
- (c) sparrowhawk (1)
- (d) transfer of energy (from the lettuce to the snail) (1) ignore 'the snail eats the lettuce' on its own
Question 5
The table shows what each organism in a woodland food web eats. (a) State the number of different organisms that eat caterpillars. [1] (b) Name one organism that is both a primary consumer and a secondary consumer. [1] (c) Define the term food web. [1] (d) Suggest what happens to the number of owls if all the blue tits are killed by disease. [1]
| Organism | Eats |
|---|---|
| Oak leaves | (producer) |
| Caterpillar | Oak leaves |
| Mouse | Oak leaves, caterpillar |
| Blue tit | Caterpillar |
| Owl | Mouse, blue tit |
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- (a) 2 / mouse and blue tit (1)
- (b) mouse (1)
- (c) a network of interconnected food chains (1)
- (d) owls decrease because there is less food (1) allow owls stay about the same because they eat more mice instead; ignore 'owls stay the same' without a reason
Question 6
Which organism gets its energy from dead or waste organic material?
- A producer
- A herbivore
- A decomposer
- A secondary consumer
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Answer: C (1)
Question 7
Fishing boats catch large numbers of a fish that is eaten by seals and that eats small crustaceans. (a) State the term for catching a species faster than it can replace itself. [1] (b) Describe the effect of this on the seal population and explain your answer. [2] (c) Describe two ways in which introducing a foreign species to a habitat can affect the food web. [2]
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- (a) overharvesting / overfishing (1)
- (b) seal population decreases / seals die or move away (1)
- (b) because there is less food (fish) for them to eat (1)
- (c) the foreign species may eat native species so their numbers fall (1)
- (c) the foreign species may compete with native species for food so their numbers fall (1) allow it becomes a new food source so its predators increase