Single-celled pond organisms have contractile vacuoles that maintain water balance within each cell. This is a an example of what scientific principle?

The correct answer is homeostasis.

Explanation:

A self-regulating procedure taking place within an organism, which permits them to sustain a stable internal condition level is termed as homeostasis. In case, if an organism fails to sustain homeostatic balance, the eventual result would be death. Water balance, temperature, salt concentration, and pH are some of the several internal conditions, which are required to maintain comparatively stability.

Some of the single-celled pond organisms like paramecium comprise contractile vacuoles, which remove additional water out of the cell. As water balance is a part of sustaining homeostatic balance for an organism, thus one can study homeostasis by witnessing the modifications within the contractile vacuole when the species is placed in distinct solutions.

a fossil fuel is a fuel formed by natural processes, such as anaerobic decomposition of buried dead organisms, containing energy originating in ancient photosynthesis.[1] the age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years.[2] fossil fuels contain high percentages of carbon and include petroleum, coal, and natural gas.[3] other commonly used derivatives include kerosene and propane. fossil fuels range from volatile materials with low carbon to hydrogen ratios like methane, to liquids like petroleum, to nonvolatile materials composed of almost pure carbon, like anthracite coal. methane can be found in hydrocarbon fields either alone, associated with oil, or in the form of methane clathrates.

the theory that fossil fuels formed from the fossilized remains of dead plants by exposure to heat and pressure in the earth's crust over millions of years was first introduced by andreas libavius "in his 1597 alchemia [alchymia]" and later by mikhail lomonosov "as early as 1757 and certainly by 1763".[4] the first use of the term "fossil fuel" was by the german chemist caspar neumann, in english translation in 1759.[5]

in 2017 the world's primary energy sources consisted of petroleum (34%), coal (28%), natural gas (23%), amounting to an 85% share for fossil fuels in primary energy consumption in the world.[6] non-fossil sources in 2006 included nuclear (8.5%), hydroelectric (6.3%), and others (geothermal, solar, tidal, wind, wood, waste) amounting to 0.9%.[7] world energy consumption was growing at about 2.3% per year. in 2015 about 18% of worldwide consumption was from renewable sources.[8]

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