AP EcoSystem (54) Quiz

An energy pyramid is a graphical representation that illustrates the flow of energy through different trophic levels in an ecosystem. It shows the amount of energy available at each level, with the primary producers (such as plants) at the bottom and the top predators at the top. As energy is transferred from one level to another, it decreases, resulting in a pyramid shape. Therefore, the correct answer is "the amount of energy at each trophic level."

The energy pyramid shows the flow of energy in an ecosystem, with producers at the bottom and consumers at higher levels. As energy moves up the pyramid, it decreases because energy is lost as heat or used for metabolic processes. In this case, if the producers have 7000 kcal of energy, the energy available for the Sheephead fish would be less than that. The correct answer of 70 kcal suggests that only 1% of the energy from the producers is available for the Sheephead fish.

The correct answer is "All of these" because all the mentioned activities contribute to the release of carbon dioxide into the atmosphere. Burning fossil fuels like coal and gasoline, burning wood, cattle production, and heating with natural gas all release carbon dioxide as a byproduct. Therefore, all of these activities are responsible for the increased release of carbon dioxide into the atmosphere.

Birds would occupy pyramid level B. This is because birds are secondary consumers, meaning they eat primary consumers, which in this case would be the insects that feed on corn. Pyramid level B represents the secondary consumers in the food chain.

Photosynthetic organisms are capable of producing their own food through the process of photosynthesis. They convert sunlight, water, and carbon dioxide into glucose and oxygen. Primary producers are organisms that can produce their own food, and autotrophs are organisms that can create organic compounds from inorganic substances. Therefore, the term "primary producer and autotroph" is synonymous with photosynthetic organisms.

Producers represent the largest amount of organisms in the food pyramid. Producers, such as plants and algae, are able to convert sunlight into energy through photosynthesis. They form the base of the food pyramid and provide food and energy for all other organisms. As a result, there are generally more producers than any other level in the food pyramid.

The correct answer is "The Giant Sea Bass is a predator of the Sheephead". This relationship is indicated by the direction of the arrow in the pyramid, showing that the Giant Sea Bass consumes the Sheephead. In a predator-prey relationship, one organism (the predator) hunts and consumes another organism (the prey) for food.

Photosynthetic organisms, such as plants and algae, use carbon dioxide (CO2) from the atmosphere and dissolved in water as their primary source of carbon. During photosynthesis, they convert CO2 into glucose and other organic compounds, using sunlight as an energy source. Bicarbonate in the water, nitrate in the soil, dissolved phosphate in water, and carbonic acid in rain are not the primary sources of carbon for photosynthetic organisms.

The key factor that limits the number of trophic levels in an ecosystem is energy loss. As energy moves through the food chain, it is transferred from one organism to another, but not all of it is absorbed and utilized. Each transfer of energy results in a loss of energy, often in the form of heat. This energy loss limits the amount of energy available to support higher trophic levels, as there is not enough energy left to sustain a large number of organisms at the top of the food chain.

Net primary productivity represents the amount of biomass that is produced by plants through photosynthesis, minus the amount of biomass that is used by plants for their own respiration. It is the measure of the energy that is available for consumption by herbivores and higher trophic levels in an ecosystem. This measure is important as it indicates the productivity and efficiency of an ecosystem in converting solar energy into plant biomass. The correct answer, "the amount of biomass in excess of that needed to support plant cell respiration," accurately describes the concept of net primary productivity.

The major atmospheric components of Earth are carbon dioxide, oxygen, and nitrogen. This is because nitrogen makes up the largest portion of Earth's atmosphere, followed by oxygen, and then carbon dioxide.

Photosynthetic organisms, such as plants and algae, are capable of fixing carbon through the process of photosynthesis. During photosynthesis, these organisms use sunlight, water, and carbon dioxide to produce glucose and oxygen. The carbon dioxide is converted into organic compounds, effectively fixing carbon from the atmosphere. This process is crucial for the carbon cycle and plays a vital role in maintaining the balance of carbon dioxide in the atmosphere. Primary consumers, decomposers, bacterial decomposers, and the burning of organic matter are not directly involved in the process of carbon fixation.

Gross primary productivity refers to the total amount of organic matter produced by plants through photosynthesis in an ecosystem. It represents the energy available for consumption by other organisms in the food chain. This measurement includes all the organic matter produced, regardless of whether it is used by the plants for their own growth or consumed by herbivores. It provides an estimate of the overall productivity and energy flow within the ecosystem.

The statement "There is a one-way flow of energy through the food webs of ecosystems" reflects a key concept about ecosystems. This concept refers to how energy is transferred from one organism to another in a linear manner within an ecosystem. Energy flows from producers (plants) to consumers (animals), and it is not recycled back to the producers. This one-way flow of energy is essential for the functioning and stability of ecosystems.

Nitrogen fixation is the process of converting atmospheric nitrogen into a usable form by living organisms. While corn, algae, lichens, and photosynthetic producers play important roles in ecosystems, they do not have the ability to fix nitrogen. Bacteria, specifically nitrogen-fixing bacteria, have the capability to convert atmospheric nitrogen into ammonia, which can then be used by other organisms. Therefore, bacteria are the correct answer for the process of nitrogen fixation.