gross primary productivity
(noun)
rate at which photosynthetic primary producers incorporate energy from the sun
Examples of gross primary productivity in the following topics:
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Productivity within Trophic Levels
- Productivity, measured by gross and net primary productivity, is defined as the amount of energy that is incorporated into a biomass.
- The rate at which photosynthetic primary producers incorporate energy from the sun is called gross primary productivity.
- An example of gross primary productivity is the compartment diagram of energy flow within the Silver Springs aquatic ecosystem .
- The net productivity is then available to the primary consumers at the next trophic level.
- Explain the concept of primary production and distinguish between gross primary production and net primary production
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Abiotic Factors Influencing Plant Growth
- Temperature and moisture are important influences on plant production (primary productivity) and the amount of organic matter available as food (net primary productivity).
- Almost all life on earth is directly or indirectly reliant on primary production.
- The organisms responsible for primary production, known as primary producers or autotrophs, form the base of the food chain.
- Net primary productivity is an estimation of all of the organic matter available as food.
- The magnitude and distribution of global primary production varies between biomes.
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Protists as Primary Producers, Food Sources, and Symbionts
- The protists themselves and their products of photosynthesis are essential, directly or indirectly, to the survival of organisms ranging from bacteria to mammals .
- As primary producers, protists feed a large proportion of the world's aquatic species.
- (On land, terrestrial plants serve as primary producers. ) In fact, approximately one-quarter of the world's photosynthesis is conducted by protists, particularly dinoflagellates, diatoms, and multicellular algae.
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Ecological Pyramids
- Even in smaller numbers, primary producers in forests are still capable of supporting other trophic levels.
- The plants (primary producers) of the Silver Springs ecosystem make up a large percentage of the biomass found there.
- However, the phytoplankton in the English Channel example make up less biomass than the primary consumers, the zooplankton.
- As with inverted pyramids of numbers, the inverted biomass pyramid is not due to a lack of productivity from the primary producers, but results from the high turnover rate of the phytoplankton.
- Pyramids of energy are always upright, since energy is lost at each trophic level; an ecosystem without sufficient primary productivity cannot be supported.
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Transferring of Energy between Trophic Levels
- $TLTE=\frac { production\quad at\quad present\quad trophic\quad level }{ production\quad at\quad previous\quad trophic\quad level } x100$
- Another main parameter that is important in characterizing energy flow within an ecosystem is the net production efficiency.
- Net consumer productivity is the energy content available to the organisms of the next trophic level.
- Primary producers are outlined in green, primary consumers in orange, secondary consumers in blue, and tertiary (apex) consumers in purple.
- For example, the opossum shrimp eats both primary producers and primary consumers.
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Secondary Active Transport
- Unlike in primary active transport, in secondary active transport, ATP is not directly coupled to the molecule of interest.
- As sodium ion concentrations build outside the plasma membrane because of the action of the primary active transport process, an electrochemical gradient is created.
- This secondary process is also used to store high-energy hydrogen ions in the mitochondria of plant and animal cells for the production of ATP.
- An electrochemical gradient, created by primary active transport, can move other substances against their concentration gradients, a process called co-transport or secondary active transport.
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Immunological Memory
- During the adaptive immune response to a pathogen that has not been encountered before, known as the primary immune response, plasma cells secreting antibodies and differentiated T cells increase, then plateau over time.
- The result is a more rapid production of immune defenses.
- Memory B cells that differentiate into plasma cells output ten to hundred-fold greater antibody amounts than were secreted during the primary response .
- Vaccination is based on the knowledge that exposure to noninfectious antigens, derived from known pathogens, generates a mild primary immune response .
- In the primary response to infection, antibodies are secreted first from plasma cells.
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Pineal Gland and Gonads
- The pineal gland is responsible for melatonin production, while the gonads secrete hormones relating to sexual characteristic development.
- The rate of melatonin production is affected by the photoperiod.
- Their main role is the production of steroid hormones.
- Testosterone, the most prominent androgen in males, stimulates the development and functioning of the primary sex organs .
- The testes produce androgens, such as testosterone, which regulate primary sex organ development and function, as well as the development of secondary sex characteristics and the production of sperm cells.
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Production of Vaccines, Antibiotics, and Hormones
- Biotechnological advances in gene manipulation techniques have further resulted in the production of vaccines, antibiotics, and hormones.
- The antigen is then introduced into the body to stimulate the primary immune response and trigger immune memory.
- Antibiotics are biotechnological products that inhibit bacterial growth or kill bacteria.
- Previously, it was only possible to treat diabetes with pig insulin, which caused allergic reactions in humans because of differences in the gene product.
- The bacteria was then grown and the hormone isolated, enabling large scale commercial production.
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Gametogenesis (Spermatogenesis and Oogenesis)
- Gametogenesis, the production of sperm and eggs, takes place through the process of meiosis.
- The production of sperm is called spermatogenesis and the production of eggs is called oogenesis.
- The cell starting meiosis is called a primary oocyte.
- This results in the primary oocyte finishing the first meiotic division.
- Meiosis begins with a cell called a primary spermatocyte.