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Questions and Answers
What is the major factor governing carbon input to ecosystems?
What is the major factor governing carbon input to ecosystems?
What is the process by which most carbon and chemical energy enter ecosystems?
What is the process by which most carbon and chemical energy enter ecosystems?
What is Gross Primary Production (GPP)?
What is Gross Primary Production (GPP)?
What is responsible for both light-harvesting and carbon-fixation reactions in the light?
What is responsible for both light-harvesting and carbon-fixation reactions in the light?
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What is the energy content of organic matter in ecosystems?
What is the energy content of organic matter in ecosystems?
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What is the primary factor determining differences among ecosystems in annual GPP?
What is the primary factor determining differences among ecosystems in annual GPP?
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What have human activities done to the rate at which carbon enters the terrestrial biosphere?
What have human activities done to the rate at which carbon enters the terrestrial biosphere?
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Study Notes
Photosynthesis and Carbon Input in Ecosystems
- Photosynthesis directly supports plant growth and produces organic matter consumed by animals and soil microbes.
- Carbon from photosynthesis makes up almost half of the organic matter on Earth, while hydrogen and oxygen account for the remainder.
- Human activities have significantly modified the rate at which carbon enters the terrestrial biosphere, increasing atmospheric CO2 by 30%.
- The availability of water and nutrients is the major factor governing carbon input to ecosystems.
- Photosynthesis is the process by which most carbon and chemical energy enter ecosystems.
- The availability of reactants such as light energy and CO2, temperature, and nitrogen availability are the proximate controls over photosynthesis by a single leaf.
- Gross primary production (GPP) is the photosynthesis at the scale of ecosystems, which varies diurnally and seasonally.
- Differences among ecosystems in annual GPP are determined primarily by the quantity of leaf area and the length of time that this leaf area is photosynthetically active.
- Carbon and energy are linked as they move through ecosystems because the same processes govern their entry, transfer, and loss.
- The energy content of organic matter is relatively constant at about 20kJ g-1 of ash-free dry mass, while the carbon concentration is variable.
- The biochemistry of photosynthesis involves light-harvesting reactions that transform light energy into a temporary form of chemical energy and carbon-fixation reactions that convert CO2 into sugars.
- Chloroplasts, organelles inside the mesophyll cells of green leaves, are responsible for both groups of reactions in the light.
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Description
Test your knowledge on the fundamental role of photosynthesis and carbon input in ecosystems with this informative quiz. From the biochemistry of photosynthesis to the factors governing carbon input, this quiz covers it all. Sharpen your understanding of the processes that support plant growth and sustain life on Earth, including the impact of human activities on the terrestrial biosphere. Whether you're a student or an environmental enthusiast, this quiz is a great way to reinforce your knowledge and learn something new.
