Environmental Science Ecosystems and Ecology 2 — Questions and Answers
Question 1: Which biome is characterized by permafrost, low precipitation, and very short growing seasons?
- Taiga
- Tundra (Correct answer)
- Temperate deciduous forest
- Grassland
Correct answer: Tundra
The tundra biome has permanently frozen subsoil (permafrost) and supports only low-growing vegetation.
Question 2: What is the term for species that significantly shape their community's structure, often out of proportion to their abundance?
- Invasive species
- Endemic species
- Keystone species (Correct answer)
- Pioneer species
Correct answer: Keystone species
Keystone species have a disproportionately large effect on their ecosystem relative to their biomass or numbers.
Question 3: Which type of symbiosis benefits one organism while the other is neither harmed nor helped?
- Mutualism
- Parasitism
- Commensalism (Correct answer)
- Competition
Correct answer: Commensalism
Commensalism describes a relationship where one organism benefits and the other is unaffected.
Question 4: The gradual process by which a community changes over time toward a stable climax community is called:
- Evolution
- Ecological succession (Correct answer)
- Biotic turnover
- Adaptive radiation
Correct answer: Ecological succession
Ecological succession is the sequential development of communities in an area over time.
Question 5: What is the zone of an aquatic ecosystem where photosynthesis can occur due to sufficient light penetration?
- Benthic zone
- Aphotic zone
- Photic zone (Correct answer)
- Abyssal zone
Correct answer: Photic zone
The photic zone is the sunlit upper layer of water where enough light exists for photosynthesis.
Question 6: Which nutrient cycle is most directly affected by combustion of fossil fuels?
- Nitrogen cycle
- Phosphorus cycle
- Carbon cycle (Correct answer)
- Sulfur cycle
Correct answer: Carbon cycle
Burning fossil fuels releases stored carbon as CO₂, significantly altering the natural carbon cycle.
Environmental Science Ecosystems and Ecology 2
Which biome is characterized by permafrost, low precipitation, and very short growing seasons?