Biomes & Ecology
These two variables influence/determine biomes.
BONUS (100pts): This biome is characterized by permafrost that prevents deep root systems.
What is precipitation and temperatures?
BONUS: What is tundra?
The Green Revolution dramatically impacted world populations.
Name one major benefit and one significant environmental drawback associated with these practices.
What is increased crop yield or food security (benefit), and soil degradation, eutrophication, loss of biodiversity, increased water use, or higher fossil fuel inputs (drawback)?
This is the process causing stratospheric reduction in ozone.
BONUS: 300 if you show chemical equation walk through
What is the breakdown of CFCs by UV radiation releasing chlorine atoms that catalyze ozone depletion?
These are the primary and secondary pollutants related to photochemical smog.
Primary Pollutants (directly emitted):
Nitrogen oxides (NO and NO₂, collectively NOₓ)
– Released mainly from vehicles and industrial combustion.
Volatile Organic Compounds (VOCs)
– Evaporated from gasoline, solvents, paints, and vegetation.
Secondary Pollutants (formed in the atmosphere through reactions):
Tropospheric ozone (O₃)
– Formed when NO₂ is broken by sunlight and free oxygen bonds with O₂.
A car emits 1.39 g of NOx per mile and is driven 22,000 miles per year for 15 years. Using dimensional analysis, determine the total emissions in g of NOx over its usage.
What is 458,000 g?
A tropical rainforest has an average net primary productivity (NPP) of 3,200 g C/m²/year and an average respiration loss (R) of 1,000 g C/m²/year.
Calculate the GPP.
What is 4,200 g C/m²/year?
A city’s stormwater system frequently overflows during heavy rainfall, carrying pollutants into nearby rivers. Urban planners want to decrease runoff volume and increase groundwater recharge.
Propose one specific land-use or infrastructure strategy the city could implement to reduce stormwater runoff.
What is installing permeable pavement, adding bioswales or rain gardens, constructing green roofs, or increasing tree canopy cover?
As global temperatures rise, Arctic sea ice melts and kicks off a feedback loop related to changing reflectivity. This is the type of feedback loop and the process occurring.
What is the ice–albedo positive feedback loop, in which lower albedo from open water increases heat absorption and further accelerates warming?
A toxin such as mercury increases in concentration in a single organism over time, but becomes even more concentrated at higher trophic levels, posing the greatest risk to apex predators.
Identify the process occurring across trophic levels.
What is biomagnification?
Arctic sea levels rose from 10 mm to 70 mm over a 20-year period. Determine the percent change.
What is 600%?
When two species utilize different parts of the same resource—such as feeding at different heights in a tree—this ecological mechanism reduces competition.
What is resource partitioning?
When siting a new sanitary landfill, engineers must choose a soil type that minimizes infiltration to prevent leachate from entering groundwater. Given clay, silt, and sand, which soil type would be most appropriate and why?
What is clay, because its small particle size and low permeability limit water movement through the soil?
Researchers test whether different blends of ethanol and gasoline affect the amount of carbon monoxide emitted from car exhaust. They run engines using 10%, 20%, and 40% ethanol blends and measure exhaust composition for each.
Identify the independent variable and the dependent variable in this experiment.
What is:
IV: Percentage of ethanol in the fuel blend; DV: Amount of carbon monoxide emitted.
Some pollutants, even at very low concentrations, can bind to hormone receptors and interfere with normal growth and reproductive processes.
BONUS 100: Name one!
What are endocrine disruptors?
A country has an annual population growth rate of 1.07% in 2025. What year will the population to double?
What is 2090?
These are two descriptors for the following species:
- Produces 2–3 offspring per year
Offspring have high parental care
The species requires a narrow range of habitat conditions
The species has a long lifespan
Population size remains relatively stable near carrying capacity
What is K-selected and specialist?
After a forested hillside is clear-cut, a nearby stream shows a fish kill occur. This is the mechanism that causes the fish kill.
What is sediment from erosion increasing turbidity, which blocks sunlight, reduces photosynthesis by aquatic plants, and decreases DO?
(Also acceptable: sediment covering benthic habitat → reduced oxygen exchange; increased water temperature from turbidity → lower DO.)
A country expands hydroelectric capacity by building a new dam. Downstream coastal communities report increased beach loss. Explain the mechanism linking hydroelectricity to coastal erosion.
What is "sediment becomes trapped behind the dam, reducing downstream deposition and accelerating coastal erosion"?
This is the chemical equation occurring in the ocean as result of increasing carbon emissions.
CO2(aq)+H2O→H2CO3→H++HCO3−
Cesium-137, with a half-life of 30 years, sample starts at 4g. Determine the remaining Cesium-137 after 120 years.
What is 0.25g?
These are the types of __________—the benefits ecosystems provide to humans for free.
Name all four categories and give one example of each.
What are ecosystem services?
The four types are:
Provisioning services — example: freshwater, timber, food, medicines
Regulating services — example: climate regulation, pollination, water purification
Support (Habitat) services — example: nutrient cycling, soil formation, primary productivity
Cultural services — example: recreation, aesthetic value, spiritual significance
A farmer wants to maintain long-term soil fertility, reduce dependence on synthetic fertilizers, and decrease erosion.
Name one sustainable agricultural practice the farmer could adopt and explain how it supports soil health.
What is crop rotation, cover cropping, contour plowing, terracing, reduced tillage, or adding organic compost—each of which improves soil structure, increases nutrients, and/or reduces erosion?
A small hydroelectric turbine produces 12,000 watts of electrical power and operates continuously at 40% efficiency. What is the amount of energy produced per year?
What is 42,048 kWh?
A country shows declining birth rates, low death rates, rapid urbanization, and increasing access to education for women. Its population is still growing, but at a slowing rate.
Identify which stage of the demographic transition the country is in and explain why based on these trends.
What is Stage 3 (the industrial stage), because birth rates begin to fall while death rates remain low, leading to slower—but still positive—population growth?
A country has a population of 50 million people.
During the past year, its population data include:
Crude birth rate (CBR): 18 births per 1,000 people
Crude death rate (CDR): 9 deaths per 1,000 people
Crude immigration rate (CIR): 5 immigrants per 1,000 people
Crude emigration rate (CER): 3 emigrants per 1,000 people
Determine the country's annual population growth rate?
What is 1.1%?