AS Associate Of Science In Environmental Science 2 — Questions and Answers
Question 1: What is the nitrogen cycle's role in ecosystems?
- Converting sunlight into chemical energy
- Circulating nitrogen from the atmosphere to living organisms and back (Correct answer)
- Filtering water through soil layers
- Breaking down organic matter into carbon dioxide
Correct answer: Circulating nitrogen from the atmosphere to living organisms and back
The nitrogen cycle describes the movement of nitrogen through the atmosphere, soil, water, and living organisms, making it available for plant growth and protein synthesis.
Question 2: Which type of pollution refers to contaminants that enter water from diffuse sources across large land areas?
- Point source pollution
- Thermal pollution
- Non-point source pollution (Correct answer)
- Groundwater pollution
Correct answer: Non-point source pollution
Non-point source pollution comes from diffuse sources, such as agricultural runoff, urban stormwater, and atmospheric deposition, making it difficult to regulate at a single discharge point.
Question 3: What is the term for the variety and variability of life forms within a given ecosystem or on Earth?
- Ecological succession
- Biodiversity (Correct answer)
- Biomass
- Trophic structure
Correct answer: Biodiversity
Biodiversity refers to the variety of life at all levels — genetic diversity, species diversity, and ecosystem diversity — and is a key indicator of ecosystem health.
Question 4: Which process converts ammonia (NH₃) in soil into nitrates that plants can absorb?
- Nitrogen fixation
- Denitrification
- Nitrification (Correct answer)
- Ammonification
Correct answer: Nitrification
Nitrification is the two-step microbial process in which soil bacteria (Nitrosomonas and Nitrobacter) convert ammonia first to nitrite and then to nitrate, which plants absorb.
Question 5: What is the greenhouse effect?
- The warming of the Earth caused by the reflection of sunlight off ice caps
- The process by which atmospheric gases trap heat radiated from Earth's surface (Correct answer)
- The cooling effect of aerosols in the atmosphere
- The depletion of the ozone layer
Correct answer: The process by which atmospheric gases trap heat radiated from Earth's surface
The greenhouse effect occurs when greenhouse gases (CO₂, CH₄, H₂O vapor, N₂O) absorb and re-emit infrared radiation from Earth's surface, warming the lower atmosphere.
Question 6: Which of the following best describes sustainable development?
- Economic growth that prioritizes profit over environmental protection
- Development that meets present needs without compromising the ability of future generations to meet their own needs (Correct answer)
- Development that avoids all use of natural resources
- Economic development limited to wealthy nations
Correct answer: Development that meets present needs without compromising the ability of future generations to meet their own needs
Sustainable development, defined by the Brundtland Commission in 1987, balances economic, social, and environmental needs so that current development does not deplete resources for future generations.
AS Associate Of Science In Environmental Science 2
What is the nitrogen cycle's role in ecosystems?