CIE iGCSE Co-Ordinated Science B18.1 Energy flow Exam Style Questions Paper 2
▶️ Answer/Explanation
All four listed processes require energy released by respiration inside the organism’s cells.
Muscle contraction, cell division, and excretion all use up chemical energy, and maintaining a constant body temperature requires continual heat production.
Since this energy is used or lost as heat rather than passed on, all four processes reduce the energy available to the next trophic level.
✅ Answer: (A)
Muscle contraction, cell division, and excretion all use up chemical energy, and maintaining a constant body temperature requires continual heat production.
Since this energy is used or lost as heat rather than passed on, all four processes reduce the energy available to the next trophic level.
✅ Answer: (A)
▶️ Answer/Explanation
An ecosystem is defined as a unit made up of all the organisms in a given area interacting with each other and with the non-living parts of their environment.
Option B describes a population, and A and D only describe parts of an ecosystem (food chains and energy transfer), not the whole system.
✅ Answer: (C)
Option B describes a population, and A and D only describe parts of an ecosystem (food chains and energy transfer), not the whole system.
✅ Answer: (C)
▶️ Answer/Explanation
Decomposers, such as bacteria and fungi, feed on dead organisms and organic waste (like faeces), breaking them down to release energy and recycle nutrients.
Producers make their own food by photosynthesis, while herbivores and carnivores feed on living plants or animals rather than dead remains.
This makes decomposers the only group that obtains energy specifically from dead organic matter.
✅ Answer: (B)
Producers make their own food by photosynthesis, while herbivores and carnivores feed on living plants or animals rather than dead remains.
This makes decomposers the only group that obtains energy specifically from dead organic matter.
✅ Answer: (B)
▶️ Answer/Explanation
Carnivores obtain energy only from other animals, and herbivores only from producers, so neither draws from every trophic level.
Producers make their own energy from sunlight and don’t feed on other organisms at all.
Decomposers break down dead matter and waste from producers, herbivores, and carnivores alike, so they obtain energy from organisms at every trophic level.
✅ Answer: (B)
Producers make their own energy from sunlight and don’t feed on other organisms at all.
Decomposers break down dead matter and waste from producers, herbivores, and carnivores alike, so they obtain energy from organisms at every trophic level.
✅ Answer: (B)
Question
A student observes that a substance X does not flow.
Which statement about substance X is correct?
(A) It can be either a gas or a liquid.
(B) It can only be a gas.
(C) It can only be a liquid.
(D) It can only be a solid.
▶️Answer/Explanation
Ans: D