1. 1
   Camels are well adapted to survive in hot, dry desert environments. They have wide, flat feet that spread their weight on loose sand, they are able to tolerate large changes in body temperature without sweating excessively, and they tend to travel and feed during the cooler parts of the day, resting in shade during the hottest hours.

   (a)

   Camels living in hot, dry desert environments have unusually wide, flat feet that spread their weight and prevent them from sinking into loose sand as they walk. What type of adaptation is this wide, flat foot shape?

   [1 mark]

   • AStructural adaptation
   • BBehavioural adaptation
   • CPhysiological adaptation
   • DGenetic mutation

   (b)

   Camels are able to tolerate large fluctuations in their internal body temperature, rising several degrees during the day and falling again at night, without needing to sweat heavily to cool down as most mammals would. What type of adaptation is this ability to tolerate large changes in internal body temperature?

   [1 mark]

   • AStructural adaptation
   • BBehavioural adaptation
   • CPhysiological adaptation
   • DPredator-prey adaptation

   (c)

   Camels tend to travel and feed during the cooler early morning and evening hours, resting in any available shade during the hottest part of the day. Explain what type of adaptation this is, and how it increases a camel's chances of survival in the desert.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   Polar bears are adapted to survive in the extremely cold Arctic environment. They have a thick layer of blubber beneath their skin for insulation, small ears and a compact body shape that reduces heat loss, thick white fur that provides further insulation and camouflage against snow, and they are able to slow their metabolism during periods of food scarcity.

   (a)

   Polar bears living in the Arctic have a thick layer of fat (blubber) beneath their skin, which helps to insulate their bodies against the extreme cold. What type of adaptation is this thick layer of blubber?

   [1 mark]

   • AChemical adaptation
   • BBehavioural adaptation
   • CPhysiological adaptation
   • DStructural adaptation

   (b)

   Compared with many mammals living in warmer climates, polar bears have relatively small, rounded ears and a compact body shape. How does this compact body shape with small extremities help a polar bear survive in the Arctic?

   [1 mark]

   • AIt increases the surface area to volume ratio, increasing heat loss
   • BIt decreases the surface area to volume ratio, reducing heat loss
   • CIt has no effect on heat loss
   • DIt increases the polar bear's speed to help it catch prey

   (c)

   Explain two different ways in which the polar bear's thick, white fur helps it to survive in the Arctic.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   Deep-sea anglerfish live in complete darkness at extreme water pressure, far below the depth that sunlight can penetrate. Female anglerfish have a modified fin spine projecting above their head, tipped with a light-producing structure containing bioluminescent bacteria, used to lure prey, and their bodies show several further adaptations that allow them to survive the crushing pressure and permanent darkness of the deep ocean.

   (a)

   Describe the type of adaptation shown by this light-producing lure, and explain how it increases the anglerfish's chances of survival in the deep sea.

   [3 marks]

   (b)

   In addition to their light-producing lure, deep-sea anglerfish have very flexible jaws and stomachs that can expand to swallow prey much larger than themselves, and their bodies lack the rigid, gas-filled swim bladder found in many shallower-water fish, instead having softer, more flexible tissues throughout their bodies. Explain how each of these two further adaptations helps the anglerfish survive in the deep-sea environment.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   The fennec fox, which lives in the hot Sahara desert, has unusually large ears relative to its small body size, while the closely related Arctic fox, which lives in the freezing Arctic tundra, has much smaller, rounder ears and a more compact, rounded body shape. Biologists studying these two closely related species use them as a classic example of how surface area to volume ratio can shape adaptations to very different climates.

   (a)

   Explain, using the concept of surface area to volume ratio, why these two closely related species of fox have evolved such different ear sizes and body shapes suited to their contrasting environments.

   [6 marks]

   (b)

   A wildlife park is considering relocating a small breeding population of Arctic foxes to a much warmer nature reserve, as part of a wider conservation plan, without making any changes to the animals themselves. Using your understanding of adaptations and surface area to volume ratio, evaluate whether this Arctic fox population is likely to survive and thrive in a significantly warmer environment, and discuss what this reveals about the relationship between adaptations and the specific environment a species has evolved in.

   [6 marks]

   Total for question 4: 12 marks

End of questions