Question 1

Forests along rivers in the Pacific Northwest that have lost their salmon populations are less productive because the

Accepted Answer

Salmon play a crucial role in the nutrient cycle of river ecosystems in the Pacific Northwest. When they die, their bodies decompose, releasing nitrogen and other nutrients into the soil, which benefits the forest growth. The loss of salmon populations means the loss of an important source of nitrogen, leading to less productive forests.

Question 2

Farmers often include legumes as part of their normal crop rotation. This practice increases the overall production of their crops by

Accepted Answer

Legumes have a symbiotic relationship with nitrogen-fixing bacteria, which convert atmospheric nitrogen into a form that plants can use, effectively enriching the soil with nitrogen. This is why farmers include legumes in crop rotations to naturally replenish soil nitrogen levels, enhancing the growth of subsequent crops.

Question 3

Why is the concentration of carbon dioxide in Earthʹs atmosphere rapidly increasing?

Accepted Answer

The rapid increase in the concentration of carbon dioxide in Earth's atmosphere is primarily due to human activities, such as the burning of fossil fuels (coal, oil, and natural gas), deforestation, and various industrial processes, which release significant amounts of CO2.

Question 4

In an area with nitrogen-poor soil, legumes often dominate over other plants because they

Accepted Answer

Legumes have a symbiotic relationship with nitrogen-fixing bacteria in their root nodules, allowing them to access atmospheric nitrogen, which is abundant but not directly usable by most plants. This gives them an advantage in nitrogen-poor soils.

Question 5

Once used by an organism, carbon- and nitrogen-based nutrients are unavailable for other organisms.

Accepted Answer

Carbon and nitrogen cycle through ecosystems, being reused by different organisms in various forms, such as through decomposition, respiration, and nitrogen fixation processes.

Question 6

The greenhouse effect is the ability of

Accepted Answer

The greenhouse effect is primarily caused by certain gases in the atmosphere (such as carbon dioxide, methane, water vapor, and others) that trap heat from the sun, preventing it from escaping back into space, thus warming the Earth.

Question 7

Micronutrients

Accepted Answer

Micronutrients are essential for organisms but are required in smaller quantities compared to macronutrients, which include elements like carbon, nitrogen, and phosphorus.

Question 8

Acid deposition is the result of interference with the __________cycles.

Accepted Answer

Acid deposition, often referred to as acid rain, primarily results from the release of sulfur dioxide (SO2) and nitrogen oxides (NOx) into the atmosphere. These substances can originate from natural sources like volcanoes and wildfires, but the majority come from human activities such as the burning of fossil fuels. When these gases react with water, oxygen, and other chemicals in the atmosphere, they form sulfuric and nitric acids, which then fall to the ground as precipitation, or in dry forms. This process disrupts ecosystems, damages buildings and monuments, and can lead to the acidification of lakes and streams.

Question 9

Nitrogen is the most abundant element in the atmosphere, and a crucial component of proteins, vitamins, and nucleic acids. However, plants and other producers cannot use nitrogen in its natural form (N₂). Nitrogen has to undergo a process called nitrogen fixation. What does this process involve?

Accepted Answer

Nitrogen fixation involves the conversion of atmospheric nitrogen gas (N2) into a form that plants can use, such as ammonia (NH3). This process is carried out by certain bacteria, including those that live in a symbiotic relationship with legumes and some free-living bacteria in the soil.

Question 10

Each summer, a large ʺdead zoneʺ devoid of fish and other animals develops where the Mississippi River flows into the Gulf of Mexico. What causes this?

Accepted Answer

The "dead zone" in the Gulf of Mexico is primarily caused by large quantities of fertilizer running off from Midwestern farm fields into the Mississippi River. These fertilizers contain nutrients like nitrogen and phosphorus, which lead to excessive algae growth. When the algae die and decompose, oxygen in the water is consumed at a rate faster than it can be replenished, creating hypoxic conditions unsuitable for most marine life.

Question 11

Human-caused disturbances of the__________ cycle may be contributing to global warming.

Accepted Answer

The carbon cycle is closely linked to global warming because human activities, such as burning fossil fuels and deforestation, increase the concentration of carbon dioxide in the atmosphere, enhancing the greenhouse effect.

Question 12

When nitrogen oxides and sulfur dioxide combine with water vapor in the air, they are converted to nitric acid and sulfuric acid, respectively. This precipitation that then falls to the Earth is known as

Accepted Answer

Acid deposition is the precipitation of nitric acid and sulfuric acid from the atmosphere.

Question 13

Burning coal and oil to release energy also releases__________ , which are overloading Earth?s nutrient cycles.

Accepted Answer

Burning coal and oil releases sulfur, carbon (in the form of carbon dioxide), and nitrogen, which can disrupt Earth's nutrient cycles by contributing to pollution and climate change.

Question 14

The hydrologic cycle is different from other nutrient cycles in that

Accepted Answer

The biotic part of the hydrologic cycle plays only a small role compared to other nutrient cycles, which heavily involve biotic processes for recycling nutrients.

Question 15

The present range of the sugar maple in North America extends from the Atlantic Ocean west to the Mississippi River and from southern Ontario, Quebec, and New Brunswick south to Tennessee and Virginia. If the global temperature rises 10°C in the future, where will the range of sugar maples be found?

Accepted Answer

With a global temperature rise, species like the sugar maple are expected to migrate to cooler areas, which generally means moving farther north from their current ranges to escape the heat.

Question 16

Carbon dioxide and other greenhouse gases cause Earthʹs temperature to increase by

Accepted Answer

Greenhouse gases, including carbon dioxide, trap heat in the Earth's atmosphere by absorbing infrared radiation emitted from the Earth's surface, preventing it from escaping into space. This process is known as the greenhouse effect, and it is responsible for warming the planet.

Question 17

What are the sources of sulfur in the atmosphere?

Accepted Answer

Sulfur in the atmosphere primarily comes from human activities, such as the burning of coal, which accounts for about 75% of the total sulfur emissions. Volcanoes and hot springs also contribute to atmospheric sulfur but to a lesser extent compared to human activities.

Question 18

When you observe a lake that has been affected by acid deposition, you might expect to find

Accepted Answer

Acid deposition can lead to the leaching of aluminum, mercury, and lead into lakes, making the water clearer due to the death of fish and other aquatic life that cannot tolerate the acidic conditions and the toxic metals.

Question 19

Phosphate fertilizers have increased the amount of phosphate in lakes and other bodies of water. What effect does this increase have on the phytoplankton in the water?

Accepted Answer

Phosphate is a key nutrient for phytoplankton, and its increase in water bodies due to fertilizers stimulates their growth by providing them with essential nutrients needed for photosynthesis and growth.

Question 20

The greenhouse effect, which has become a major ecological concern, is caused by

Accepted Answer

The greenhouse effect is primarily caused by the increase in atmospheric concentrations of greenhouse gases such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). These gases trap heat in the Earth's atmosphere, leading to a warming effect.

Quiz 29: Energy Flow and Nutrient Cycling in Ecosystems

Forests along rivers in the Pacific Northwest that have lost their salmon populations are less productive because the

Farmers often include legumes as part of their normal crop rotation. This practice increases the overall production of their crops by

Why is the concentration of carbon dioxide in Earthʹs atmosphere rapidly increasing?

In an area with nitrogen-poor soil, legumes often dominate over other plants because they

Once used by an organism, carbon- and nitrogen-based nutrients are unavailable for other organisms.

The greenhouse effect is the ability of

Micronutrients

Acid deposition is the result of interference with the __________cycles.

Nitrogen is the most abundant element in the atmosphere, and a crucial component of proteins, vitamins, and nucleic acids. However, plants and other producers cannot use nitrogen in its natural form (N₂) . Nitrogen has to undergo a process called nitrogen fixation. What does this process involve?

Each summer, a large ʺdead zoneʺ devoid of fish and other animals develops where the Mississippi River flows into the Gulf of Mexico. What causes this?

Human-caused disturbances of the__________ cycle may be contributing to global warming.

When nitrogen oxides and sulfur dioxide combine with water vapor in the air, they are converted to nitric acid and sulfuric acid, respectively. This precipitation that then falls to the Earth is known as

Burning coal and oil to release energy also releases__________ , which are overloading Earth?s nutrient cycles.

The hydrologic cycle is different from other nutrient cycles in that

Carbon dioxide and other greenhouse gases cause Earthʹs temperature to increase by

What are the sources of sulfur in the atmosphere?

When you observe a lake that has been affected by acid deposition, you might expect to find

Phosphate fertilizers have increased the amount of phosphate in lakes and other bodies of water. What effect does this increase have on the phytoplankton in the water?

The greenhouse effect, which has become a major ecological concern, is caused by

Quiz 29: Energy Flow and Nutrient Cycling in Ecosystems

Forests along rivers in the Pacific Northwest that have lost their salmon populations are less productive because the

Farmers often include legumes as part of their normal crop rotation. This practice increases the overall production of their crops by

Why is the concentration of carbon dioxide in Earthʹs atmosphere rapidly increasing?

In an area with nitrogen-poor soil, legumes often dominate over other plants because they

Once used by an organism, carbon- and nitrogen-based nutrients are unavailable for other organisms.

The greenhouse effect is the ability of

Micronutrients

Acid deposition is the result of interference with the __________cycles.

Nitrogen is the most abundant element in the atmosphere, and a crucial component of proteins, vitamins, and nucleic acids. However, plants and other producers cannot use nitrogen in its natural form (N2) . Nitrogen has to undergo a process called nitrogen fixation. What does this process involve?

Each summer, a large ʺdead zoneʺ devoid of fish and other animals develops where the Mississippi River flows into the Gulf of Mexico. What causes this?

Human-caused disturbances of the__________ cycle may be contributing to global warming.

When nitrogen oxides and sulfur dioxide combine with water vapor in the air, they are converted to nitric acid and sulfuric acid, respectively. This precipitation that then falls to the Earth is known as

Burning coal and oil to release energy also releases__________ , which are overloading Earth?s nutrient cycles.

The hydrologic cycle is different from other nutrient cycles in that

Carbon dioxide and other greenhouse gases cause Earthʹs temperature to increase by

What are the sources of sulfur in the atmosphere?

When you observe a lake that has been affected by acid deposition, you might expect to find

Phosphate fertilizers have increased the amount of phosphate in lakes and other bodies of water. What effect does this increase have on the phytoplankton in the water?

The greenhouse effect, which has become a major ecological concern, is caused by

Nitrogen is the most abundant element in the atmosphere, and a crucial component of proteins, vitamins, and nucleic acids. However, plants and other producers cannot use nitrogen in its natural form (N₂) . Nitrogen has to undergo a process called nitrogen fixation. What does this process involve?