Organisms and their Environment
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Energy flow and food webs
SubtopicEnergy flow and food webs under Organisms and their Environment for Grade 11 IGCSE.
Preview questions (no answers)
- 1.
If a sheep eats grass, which term best describes the sheep's position in the food chain?
A.Producer
B.Primary consumer
C.Secondary consumer
D.Tertiary consumer
- 2.
Which of the following organisms is always situated at the first trophic level?
A.Secondary consumers
B.Herbivores
C.Producers
D.Decomposers
- 3.
In a food web or food chain diagram, what is represented by the direction of the arrows?
A.The flow of energy from one organism to the next
B.The movement of the predator towards its prey
C.The increase in biomass at each level
D.The transfer of water through the ecosystem
Download the worksheet for Organisms and their Environment - Energy flow and food webs to practice offline. It includes additional chapter-level practice questions.
Nutrient cycles (Carbon and Nitrogen)
SubtopicNutrient cycles (Carbon and Nitrogen) under Organisms and their Environment for Grade 11 IGCSE.
Preview questions (no answers)
- 1.
Which process in the carbon cycle occurs when fossil fuels like coal or oil are burned to release energy?
A.Ingestion
B.Fossilisation
C.Nitrification
D.Combustion
- 2.
Which group of organisms plays the most crucial role in breaking down dead plant and animal matter, releasing carbon back into the soil and atmosphere?
A.Primary consumers
B.Tertiary consumers
C.Decomposers
D.Producers
- 3.
In the nitrogen cycle, most plants cannot use nitrogen gas directly from the air. In what form do they primarily absorb nitrogen from the soil?
A.Ammonia gas
B.Nitrate ions
C.Nitrogen molecules
D.Amino acids
Download the worksheet for Organisms and their Environment - Nutrient cycles (Carbon and Nitrogen) to practice offline. It includes additional chapter-level practice questions.
Population size
SubtopicPopulation size under Organisms and their Environment for Grade 11 IGCSE.
Preview questions (no answers)
- 1.
Refer to the food chain provided. If the population of Frogs suddenly declines due to a disease, what is the most likely immediate effect on the Grasshopper population?
A.The Grasshopper population will decrease.
B.The Grasshopper population will increase.
C.The Grasshopper population will become producers.
D.The Grasshopper population will stay exactly the same.
- 2.
In the sigmoid growth curve of a population, what is the name of the phase where the population growth rate is at its maximum?
A.Stationary phase
B.Lag phase
C.Log (exponential) phase
D.Death phase
- 3.
Which factor is most likely to cause a population size to increase?
A.A decrease in the number of predators.
B.An increase in the rate of emigration.
C.A significant decrease in the food supply.
D.An outbreak of a highly contagious disease.
Download the worksheet for Organisms and their Environment - Population size to practice offline. It includes additional chapter-level practice questions.