1. 1
   A school aquarium contains anemone fish that live among sea anemone tentacles; the fish get protection from predators by hiding among the stinging tentacles, while the anemone benefits from food scraps dropped by the fish and from the fish chasing away anemone-eating species.

   (a)

   What term describes the close relationship between different species in a community, where each depends on others for factors such as food or shelter?

   [1 mark]

   • AInterdependence
   • BCompetition
   • CPredation
   • DExtinction

   (b)

   If the sea anemones were removed from this reef community, what would you expect to happen to the population of anemone fish that depend on them for shelter?

   [1 mark]

   • AIt would increase
   • BIt would stay exactly the same
   • CIt would become extinct immediately
   • DIt would decrease

   (c)

   Explain why removing one species, such as the sea anemone, from a community can affect the population sizes of other species, even ones not directly eaten by it.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A species of small owl that hunts at night in dense evergreen forest has unusually large eyes and extremely soft-edged feathers that make almost no sound in flight, compared with owls that hunt in open grassland.

   (a)

   What type of adaptation are the owl's large eyes, which improve its ability to see in the dark forest?

   [1 mark]

   • ABehavioural adaptation
   • BStructural adaptation
   • CFunctional adaptation
   • DGenetic mutation

   (b)

   The soft-edged feathers that reduce flight noise help the owl compete more successfully for which resource?

   [1 mark]

   • AWater
   • BTerritory
   • CFood
   • DLight

   (c)

   Explain how the owl's silent flight adaptation could give it an advantage when competing with other predators in the forest for food.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   Marine biologists studying a kelp forest recorded that kelp is eaten by sea urchins, and sea urchins are preyed upon by sea otters. Sea otters were once nearly wiped out in this area by hunting, but numbers are now recovering.

   (a)

   Explain what would be expected to happen to the sea urchin and kelp populations if sea otters were removed from this food chain.

   [3 marks]

   (b)

   The total amount of energy stored in the tissues of kelp in this kelp forest is much greater than the total amount of energy stored in the tissues of all the sea urchins combined. Explain why energy transfer between trophic levels in a food chain like this is never 100% efficient.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A city council is planning to build a new housing estate on an area of wetland just outside the city, which is currently home to several species of wading bird and amphibian found nowhere else nearby.

   (a)

   Explain how building the housing estate on this wetland could reduce local biodiversity, and describe the type of pollution that construction and the new housing could add to the area.

   [6 marks]

   (b)

   Evaluate two measures the council could put in place, alongside the housing development, to reduce its negative impact on biodiversity in the area.

   [6 marks]

   Total for question 4: 12 marks

5. 5
   A team of ecology students wants to estimate the total population of clover plants growing across a golf course rough area covering 5,000 m². They place a number of 0.5 m² sampling frames at random locations across the rough and count the clover plants inside each frame.

   (a)

   What is the term for the piece of equipment used to mark out each of these small square sampling areas?

   [1 mark]

   • ATransect
   • BPooter
   • CPitfall trap
   • DQuadrat

   (b)

   Why did the students place their sampling frames at random locations across the rough, rather than choosing locations themselves?

   [1 mark]

   • ATo avoid bias and get a representative sample
   • BTo make the frames easier to see
   • CTo save time
   • DTo make sure every frame contains the same number of clover plants

   (c)

   The students counted a mean of 4 clover plants per 0.5 m² frame. Calculate the estimated total number of clover plants across the whole 5,000 m² area of rough, showing your working.

   [2 marks]

   Total for question 5: 4 marks

6. 6
   A city recycling centre is trying to encourage residents to recycle more plastic, metal and glass waste instead of sending it to landfill sites outside the city.

   (a)

   How does sending waste to landfill, rather than recycling it, most directly reduce biodiversity?

   [1 mark]

   • AIt releases greenhouse gases that cool the climate
   • BIt has no effect on biodiversity
   • CIt uses up land that could otherwise support habitats for wildlife
   • DIt increases the number of species in the area

   (b)

   Which of these is another example of a measure that helps reduce the negative effects of human activity on biodiversity, alongside recycling?

   [1 mark]

   • AIncreasing the rate of deforestation
   • BProtecting and regenerating rare habitats
   • CDraining more wetland for farmland
   • DIncreasing the use of landfill sites

   (c)

   Explain how increasing the proportion of household waste that is recycled, rather than sent to landfill, could help to maintain biodiversity.

   [2 marks]

   Total for question 6: 4 marks

7. 7
   A nature reserve warden records that a species of dragonfly that was common in the reserve's ponds ten years ago has become much rarer since a new species of fish that eats dragonfly larvae was accidentally introduced into the ponds.

   (a)

   Explain, using the term 'biotic factor', why the introduction of the new fish species has caused the dragonfly population in the ponds to decline.

   [3 marks]

   (b)

   Explain why introducing a new predator species like this can disturb the stability of the whole pond community, not just the dragonfly population.

   [4 marks]

   Total for question 7: 7 marks

8. 8
   A species of mountain hare turns white in winter for camouflage against snow, triggered by shortening day length, and brown in summer to match bare rock and vegetation. In recent years, warmer winters mean snow now settles on the mountains for a much shorter period each year than in the past.

   (a)

   Explain how the mountain hare's seasonal colour change is an adaptation, and describe the problem that warmer winters with less snow cover are now causing for hares in this population.

   [6 marks]

   (b)

   Evaluate the likely effect of this camouflage mismatch on the mountain hare population's ability to compete with a closely related brown hare species that does not change colour and also lives on the mountain, and suggest how the mountain hare population might respond over time.

   [6 marks]

   Total for question 8: 12 marks

End of questions