Ecosystems and Energy Flow
What is the primary source of energy for most ecosystems?
Sunlight
Biodiversity refers to the variety of:
A. Plant species only
B. Genetic, species, and ecosystem diversity
C. Microorganisms in soil
D. Species that are endangered
B. Genetic, species, and ecosystem diversity
Which of the following is a point source of water pollution?
A. Fertilizer runoff
B. Urban stormwater
C. Factory discharge pipe
D. Agricultural field
C. Factory discharge pipe
Which of the following is a renewable energy source?
A. Coal
B. Wind
C. Natural gas
D. Uranium
B. Wind
Which gas is the most abundant greenhouse gas in Earth's atmosphere?
A. CO₂
B. Methane
C. Ozone
D. Water vapor
D. Water vapor
Which of the following is the best explanation for why energy pyramids typically have only 4–5 trophic levels?
A. Producers become extinct beyond the fifth level
B. Organisms evolve to limit energy use
C. There is insufficient energy transferred to support additional levels
D. Top predators control energy flow
C. There is insufficient energy transferred to support additional levels
The bottleneck effect threatens species because it:
A. Increases competition
B. Reduces genetic diversity
C. Increases population size
D. Decreases mutation rates
B. Reduces genetic diversity
What term describes the buildup of toxic substances like mercury in the tissues of organisms at increasing trophic levels?
Biomagnification
Which fossil fuel emits the most carbon dioxide per unit of energy when burned?
coal
Which pollutant is primarily responsible for the depletion of the ozone layer?
CFCs
Which process is primarily responsible for converting organic nitrogen into ammonia in decomposing biomass?
A. Ammonification
B. Denitrification
C.Assimilation
D. Nitrification
A. Ammonification
Which best describes the relationship between habitat fragmentation and extinction risk?
A. Fragmentation reduces competition and decreases extinction
B. Fragmentation increases edge effects, isolating populations
C. Fragmentation increases gene flow between populations
D. Fragmentation benefits specialist species
B. Fragmentation increases edge effects, isolating populations
A landfill with layered plastic linings and systems to collect leachate is designed to prevent what kind of environmental problem?
Groundwater contamination (or leachate pollution)
A developing country builds a hydroelectric dam for electricity. What is one ecological trade-off associated with this project?
Disruption of aquatic ecosystems or fish migration; flooding of habitats
Global warming causes positive feedback loops. Which of the following is an example?
A. Increased cloud cover reflecting sunlight
B. Melting ice reduces albedo, causing more warming
C. Increased ocean evaporation cooling the surface
D. Plants absorbing more CO₂
B. Melting ice reduces albedo, causing more warming
In which biome is net primary productivity the highest?
Tropical rainforest
An island located far from the mainland has fewer species and a higher extinction rate than a closer island of the same size. This supports what ecological theory?
Island Biogeography Theory
A city experiences respiratory problems due to a mix of nitrogen oxides and volatile organic compounds reacting under sunlight. What is this form of pollution called?
Photochemical smog
Which of the following would increase the energy return on investment (EROI) of a geothermal power plant?
A. Building it in a tectonically inactive region
B. Using deep drilling instead of shallow wells
C. Combining it with solar thermal energy
D. Locating it near an active volcanic zone
D. Locating it near an active volcanic zone
Which of the following best explains how El Niño events affect global climate patterns?
A. Increased hurricane frequency in the Atlantic
B. Strengthening of the upwelling off South America
C. Warmer Pacific waters shift weather patterns, weakening trade winds
D. Polar vortex destabilization
C. Warmer Pacific waters shift weather patterns, weakening trade winds
A tropical ecosystem has extremely high gross primary productivity but a relatively low net primary productivity. What is the most plausible explanation?
A. The system has few decomposers
B. High levels of herbivory reduce energy availability
C. Most of the energy is lost to producer respiration
D. The ecosystem is nutrient-limited
C. Most of the energy is lost to producer respiration
You’re a conservation planner trying to maintain gene flow between fragmented wildlife populations. What landscape feature should you design and implement?
Wildlife corridors (or habitat corridors)
What characteristic makes persistent organic pollutants (POPs) particularly dangerous in aquatic ecosystems?
A. They rapidly dissolve in water
B. They are broken down by sunlight
C. They bioaccumulate and biomagnify through food webs
D. They are neutralized by pH buffering
C. They bioaccumulate and biomagnify through food webs
A country transitions to primarily wind and solar power. What infrastructure challenge must it address to maintain grid reliability?
A. Increasing fossil fuel production
B. Managing variable supply through storage and smart grids
C. Switching to centralized power stations
D. Reducing overall energy consumption
B. Managing variable supply through storage and smart grids
You're designing a global climate policy. Explain the difference between mitigation and adaptation, and give one example of each.
Mitigation: Reducing the causes of climate change (e.g., cutting greenhouse gas emissions)
Adaptation: Adjusting to its effects (e.g., building sea walls to manage rising sea levels)