Unit 3 Quiz Biogeochemical Cycles

Organisms require nutrients to carry out essential life functions such as growth, reproduction, and maintenance of their bodily functions. These nutrients provide the necessary energy and building blocks for the organism's cells and tissues. Without these nutrients, organisms would not be able to perform these vital functions and would not be able to survive.

Decomposition is not part of the water cycle because it refers to the breakdown of organic matter into simpler substances, such as carbon dioxide and water. While the water cycle involves the continuous movement of water between the Earth's surface, atmosphere, and back, decomposition is a process that occurs after the death of organisms and does not directly involve the movement of water.

Plants undergo transpiration, which is a type of evaporation. Transpiration is the process by which plants release water vapor into the atmosphere through tiny pores called stomata on their leaves. This helps plants regulate their temperature, transport nutrients, and maintain their structure. Fungi, animals, and bacteria do not have the same mechanism for releasing water vapor as plants do.

Scientists are concerned about the impact humans have on the carbon cycle because they believe that we are contributing excessive amounts of CO2 to the atmosphere. This excessive CO2 can lead to global climate change, which can have severe consequences for the planet and its ecosystems. Climate change can cause rising temperatures, melting ice caps, extreme weather events, and disruptions to natural habitats. It can also result in the loss of biodiversity and negatively affect human health and well-being. Therefore, scientists are worried about the potential long-term effects of our carbon emissions on the Earth's climate system.

Energy is not recycled in the biosphere. While nitrogen, carbon, and water can all be cycled and reused within ecosystems, energy flows through the biosphere in a one-way direction. Energy enters ecosystems through the sun, is captured by plants through photosynthesis, and then transferred through the food chain as organisms consume each other. However, energy is eventually lost as heat and cannot be reused or recycled within the biosphere.

Photosynthesis is the correct answer because it is the process by which plants and some other organisms convert carbon dioxide and sunlight into glucose and oxygen. During photosynthesis, plants use the energy from sunlight to convert carbon dioxide into glucose, releasing oxygen as a byproduct. This process helps to remove carbon dioxide from the atmosphere, reducing its concentration and contributing to the balance of gases in the Earth's atmosphere.

Nitrogen fixation is the correct answer because it refers to the process of converting atmospheric nitrogen gas into a usable form for plants, such as ammonia or nitrate. Burning, lightning strikes, and legumes all contribute to this process by providing the necessary energy or bacteria to convert nitrogen gas into a form that can be taken up by plants. Transpiration, denitrification, and decomposition are all important processes in the nitrogen cycle, but they do not specifically involve the conversion of atmospheric nitrogen gas into a usable form for plants.

Nitrogen fixation is the process of converting atmospheric nitrogen into a form that can be used by living organisms. This process is primarily carried out by bacteria, specifically nitrogen-fixing bacteria. These bacteria have the ability to convert atmospheric nitrogen gas (N2) into ammonia (NH3) through a process called nitrogen fixation. This ammonia can then be used by plants and other organisms to synthesize proteins and other essential compounds. Humans, consumers, plants, and fungi do not have the ability to directly fix atmospheric nitrogen, making bacteria the correct answer.

Nitrogen fixation and denitrification involve the use of bacteria. Nitrogen fixation is the process by which certain bacteria convert atmospheric nitrogen into a form that can be used by plants. Denitrification, on the other hand, is the process by which bacteria convert nitrates back into atmospheric nitrogen. Both of these processes are essential for the cycling of nitrogen in ecosystems, and they rely on the activity of specific bacteria.

The largest impact would be on the carbon cycle. Fossil fuels, which are derived from carbon-rich materials like coal, oil, and natural gas, release large amounts of carbon dioxide when burned. This contributes to the greenhouse effect and climate change. Additionally, the extraction and combustion of fossil fuels disrupt natural carbon sinks, such as forests and oceans, which play a crucial role in balancing the carbon cycle. Therefore, the use of fossil fuels has the greatest impact on the carbon cycle.

Photosynthesis and cellular respiration are both integral parts of the carbon cycle. During photosynthesis, plants and other organisms convert carbon dioxide into glucose, releasing oxygen as a byproduct. In cellular respiration, organisms break down glucose to release energy, producing carbon dioxide as a byproduct. These processes work in tandem, with photosynthesis removing carbon dioxide from the atmosphere and cellular respiration adding it back, ensuring a continuous cycle of carbon exchange. Therefore, the correct answer is photosynthesis and cellular respiration.

Carbon is stored in the biosphere in various ways. It is present in the atmosphere as carbon dioxide, in the oceans as dissolved carbon dioxide, and underground as fossil fuels and calcium carbonate rock. These different forms of carbon storage contribute to the overall carbon cycle and play a crucial role in regulating the Earth's climate.

Carbon cycles through the biosphere in various processes such as decomposition of plants and animals, photosynthesis, and burning of fossil fuels. Transpiration, on the other hand, is the process by which water is evaporated from plants. Although transpiration is an important process in the water cycle, it does not directly involve the cycling of carbon. Therefore, the correct answer is transpiration.

Biological systems have the ability to transform matter rather than using it up completely. This means that matter can be reused and recycled within the biosphere. Instead of being consumed entirely, matter is transformed into different forms and can be utilized by other organisms. This process allows for a continuous cycle of matter within the biosphere, ensuring that resources are not depleted but rather transformed and reused by different organisms and ecosystems.

Denitrification is the process that converts nitrogen in the form of nitrates and ammonia into nitrogen gas to be released into the atmosphere. During denitrification, bacteria convert nitrates and ammonia into nitrogen gas, completing the nitrogen cycle. This process occurs in anaerobic conditions, such as waterlogged soils or sediments, where oxygen is limited. Denitrification plays a crucial role in balancing the nitrogen levels in ecosystems and helps to regulate the availability of nitrogen for plants and other organisms.

Plants are responsible for the removal of carbon dioxide from the atmosphere through the process of photosynthesis. During photosynthesis, plants absorb carbon dioxide from the air and convert it into oxygen and glucose. This helps to balance the levels of carbon dioxide in the atmosphere and is crucial for maintaining a healthy environment. While animals, bacteria, and fungi also play important roles in the carbon cycle, plants are the primary organisms responsible for removing carbon dioxide from the atmosphere.

All of the answer choices are correct because combustion, cellular respiration, and decomposition are all processes that release carbon dioxide into the atmosphere. Combustion is the process of burning fossil fuels, which releases carbon dioxide as a byproduct. Cellular respiration is the process by which cells convert glucose into energy, and one of the byproducts is carbon dioxide. Decomposition is the breakdown of organic matter, and during this process, carbon dioxide is released.

Fertilizer contains nitrogen, which is essential for plant growth. When humans apply fertilizer to fields, it increases the nitrogen levels in the soil, thereby enhancing the availability of this nutrient for plants. Nitrogen is a key component of amino acids, proteins, and chlorophyll, all of which are vital for plant growth and development. Therefore, applying fertilizer with nitrogen has the largest impact on the nitrogen cycle, as it increases the availability of this nutrient for plants to utilize.

Legumes play a crucial role in the nitrogen cycle as they host nitrogen-fixing bacteria within their root structures. These bacteria have the ability to convert atmospheric nitrogen into a form that plants can use, such as ammonia or nitrate. This process, known as nitrogen fixation, allows legumes to obtain the necessary nitrogen for their growth and development. Additionally, legumes release excess nitrogen into the soil, enriching it and making it available for other plants.

Decomposition is a major part of both the carbon cycle and the nitrogen cycle because it involves the breakdown of organic matter, releasing carbon dioxide and nitrogen back into the atmosphere. During decomposition, microorganisms break down dead plants and animals, returning nutrients to the soil and allowing them to be reused by other organisms. This process is essential for the cycling of carbon and nitrogen in ecosystems, as it helps maintain the balance of these elements and supports the growth of plants and other organisms.

When plants undergo photosynthesis, they absorb carbon dioxide (CO2) from the atmosphere. This process helps to reduce the amount of CO2 in the atmosphere. However, when the plants are burned as biomass fuel, the stored CO2 is released back into the atmosphere. Therefore, burning biomass instead of fossil fuel keeps the amount of CO2 relatively stable because the CO2 released during combustion is essentially the same CO2 that was previously absorbed by the plants during photosynthesis.

All of the answer choices are correct because fungi, animals, bacteria, and plants all play a role in returning carbon dioxide to the atmosphere. Fungi and bacteria decompose dead organic matter and release carbon dioxide through the process of decomposition. Animals, including humans, exhale carbon dioxide as a waste product of respiration. Plants also release carbon dioxide during respiration, and when they die and decompose. Therefore, all of these organisms contribute to the carbon cycle and the return of carbon dioxide to the atmosphere.