Environmental Science Summative Review

Front

T/F

Animals and Plants die, in aerobic conditions to produce CH4 or methane

Back

False

Methane (CH4) is produced in anerobic conditions

Front

T/F

Soil Bacteria is the main organism that releases Nitrogen into the Nitrogen Cycle for plants to use and be released into the atmosphere.

Back

True

nitrogen-fixing bacteria make nitrogen available for plants. while denitrifying bacteria release nitrogen back into the atmosphere.

Front

T/F

Uplift, weathering, and erosion play important roles in the Phosphorus Cycle

Back

True

• Uplift: Geological uplift can expose phosphorus-rich rocks from beneath the Earth's surface. This brings phosphorus, which is usually stored in rocks, up to areas where it can eventually enter ecosystems.

• Weathering: Once rocks containing phosphorus are exposed to the surface, physical and chemical weathering breaks them down. This releases phosphorus in a usable form, like phosphate, into the soil and water.

• Erosion: Erosion can carry phosphorus-rich soil or rock particles into bodies of water (rivers, lakes, oceans). This further distributes phosphorus across ecosystems.

Front

T/F

Infiltration of water into groundwater is disrupted by urbanization and paved roads which does not replenish aquifers.

Back

True

In undeveloped areas, when it rains, water naturally soaks into the ground, replenishing underground aquifers through the process of infiltration. This water can later be accessed by plants or slowly move into streams and rivers, maintaining water supplies.

Urbanization involves the construction of impervious surfaces, like roads, parking lots, and buildings. These surfaces prevent water from soaking into the ground.

Front

T/F

Humans use excess fertilizers for food crops and produce mass amounts of synthetic fertilizer that enter aquatic ecosystems through runoff.

Back

True

When more fertilizer is applied than plants can use, the excess remains in the soil or is washed away.

Rainfall or irrigation can carry unused fertilizers from agricultural fields into nearby streams, rivers, and eventually lakes and oceans.

This runoff introduces high levels of nitrogen and phosphorus into water bodies, which are nutrients that aquatic ecosystems don’t naturally have in large quantities.

Front

T/F

Shallow (phytoplankton) and deep marine organisms create sediments containing calcium carbonate which is an aquatic sink for carbon.

Back

True

These organisms absorb carbon dioxide (CO₂) from the water, which in turn helps regulate atmospheric CO₂ levels.

Shallow and deep marine organisms play a critical role in sequestering carbon in calcium carbonate sediments, which form an important aquatic carbon sink and help regulate the Earth's carbon cycle.

Front

T/F

Decomposition leads to the burial of organic matter and sedimentation creates fossil fuels such as coal, natural gas and crude oil within the long phase of the carbon cycle.

Back

True

Decomposition and sedimentation are crucial in the formation of fossil fuels, as organic matter is buried and transformed over geological timescales. These fossil fuels store carbon for millions of years, playing a central role in the long-term carbon cycle. When humans extract and burn fossil fuels, they rapidly release this stored carbon, affecting the balance of carbon in the atmosphere.

Front

T/F

Nitrates are converted by soil bacteria as nitrogen gas as it returns nitrogen back to the atmosphere which is nitrogen's major reservoir.

Back

False

Through the process of denitrification, soil bacteria convert nitrates into nitrogen gas, returning it to the atmosphere, which is nitrogen’s largest reservoir. This step is critical in maintaining the balance of nitrogen in ecosystems and completing the nitrogen cycle.

Front

T/F

Eutrophication (algal Blooms) is not a result of excess nitrogen but is caused by global warming and excess carbon dioxide

Back

False

Eutrophication and algal blooms are primarily driven by excess nitrogen and phosphorus in aquatic ecosystems, typically from human activities. While global warming may influence the intensity and occurrence of algal blooms, it is not the root cause. Thus, managing nutrient inputs is essential for preventing eutrophication and maintaining healthy aquatic ecosystems.