Ecology
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Species, communities and ecosystems
SubtopicSpecies, communities and ecosystems under Ecology for Grade 12 IB.
Preview questions (no answers)
- 1.
Which group of organisms is responsible for converting light energy into chemical energy within an ecosystem?
A.Saprotrophs
B.Heterotrophs
C.Detritivores
D.Autotrophs
- 2.
What is the collective term for a group of populations of different species living together and interacting with each other in an area?
A.Ecosystem
B.Community
C.Habitat
D.Niche
- 3.
In the food chain shown below, which organism represents the secondary consumer?
A.Grass
B.Grasshopper
C.Frog
D.Python
Download the worksheet for Ecology - Species, communities and ecosystems to practice offline. It includes additional chapter-level practice questions.
Preview questions (no answers)
- 1.
Based on the food chain provided in the diagram, which organism occupies the third trophic level?
A.Algae
B.Mayfly Larva
C.Trout
D.Kingfisher
- 2.
What do the arrows in a food chain represent?
A.The movement of predators to their prey
B.The cycling of minerals in the soil
C.The change in population size over time
D.The direction of energy flow between organisms
- 3.
In an ecosystem, what is the primary role of autotrophs in the flow of energy?
A.To convert light energy into chemical energy
B.To recycle nutrients from dead organic matter
C.To release energy as heat for other organisms
D.To consume primary consumers for energy
Download the worksheet for Ecology - Energy flow to practice offline. It includes additional chapter-level practice questions.
Preview questions (no answers)
- 1.
Which of the following processes increases the concentration of carbon dioxide in the atmosphere?
A.Formation of peat
B.Sedimentation of shells
C.Carbon sequestration
D.Cellular respiration
- 2.
In what form is most carbon stored when it is dissolved in the oceans?
A.Methane gas
B.Dissolved and hydrogen carbonate ions
C.Liquid glucose
D.Solid calcium phosphate
- 3.
In the carbon cycle, what is the primary role of methanogenic archaeans?
A.They produce methane () from organic matter in anaerobic conditions.
B.They oxidize methane into carbon dioxide in the atmosphere.
C.They convert carbon dioxide into glucose through chemosynthesis.
D.They facilitate the formation of limestone in marine environments.
Download the worksheet for Ecology - Carbon cycling to practice offline. It includes additional chapter-level practice questions.
Preview questions (no answers)
- 1.
According to the industrial record, what is the correlation between atmospheric concentrations and global temperatures?
A.There is no observable correlation between the two variables.
B.Temperature increases consistently before levels rise.
C.There is a strong positive correlation between increased and rising temperatures.
D.As levels increase, global temperatures show a downward trend.
- 2.
What is a likely consequence of rising global temperatures on arctic ecosystems?
A.Increased thickness of permafrost layers
B.Expansion of habitat for polar bears and walruses
C.Reduction in the distribution of coniferous forests
D.Increased rates of decomposition of detritus in previously frozen soil
- 3.
What is the primary mechanism by which greenhouse gases contribute to global warming?
A.They absorb incoming short-wave radiation from the sun.
B.They reflect ultraviolet radiation back into space.
C.They trap long-wave infrared radiation emitted by the Earth's surface.
D.They deplete the ozone layer, allowing more heat to enter.
Download the worksheet for Ecology - Climate change to practice offline. It includes additional chapter-level practice questions.