APES Ecosystems & Biodiversity — Questions and Answers
Question 1: Which term describes the variety of life across all levels of ecological organization?
- Productivity
- Biomass
- Biodiversity (Correct answer)
- Succession
Correct answer: Biodiversity
Biodiversity refers to the diversity of species, genes, and ecosystems in a given area or on the planet.
Question 2: What is a keystone species?
- An organism that is always endangered
- A species that is the most numerous
- A species with a critical ecosystem role (Correct answer)
- A recently discovered species
Correct answer: A species with a critical ecosystem role
A keystone species has a disproportionately large effect on its ecosystem relative to its abundance.
Question 3: Which process is responsible for converting atmospheric nitrogen into a usable form for plants?
- Photosynthesis
- Respiration
- Nitrogen fixation (Correct answer)
- Decomposition
Correct answer: Nitrogen fixation
Nitrogen fixation converts atmospheric nitrogen into ammonia or nitrates that plants can absorb and use.
Question 4: What typically happens to energy as it flows through a food chain?
- It increases at higher levels
- It is stored indefinitely
- It decreases at each trophic level (Correct answer)
- It is recycled back to producers
Correct answer: It decreases at each trophic level
Energy decreases at each trophic level due to metabolic processes and heat loss, leaving less energy available for higher levels.
Question 5: Which type of ecosystem has the highest biodiversity?
- Tundra
- Desert
- Temperate forest
- Tropical rainforest (Correct answer)
Correct answer: Tropical rainforest
Tropical rainforests have the highest biodiversity due to stable temperatures, high moisture, and long evolutionary history.
Question 6: What is ecological succession?
- Migration of animals
- Climatic change
- Gradual change in ecosystem communities (Correct answer)
- Seasonal reproduction
Correct answer: Gradual change in ecosystem communities
Ecological succession is the natural process of change in species composition over time within an ecosystem.
APES Ecosystems & Biodiversity
Which term describes the variety of life across all levels of ecological organization?