Answer20 biologists designed an experiment to test the effect of compost on the development of root crops. they tested several different crops, including carrots, potatoes, beets, and onions. they grew most of the plants in the greenhouse, but due to space issues, they had to grow some outdoors. they gave all the plants the same amount of compost. they obtained the compost from a local farmer and from the local hardware store. they ran out of the farmer’s compost, so some of the plants received that compost when the seeds were planted and other plants got hardware store compost after the plants had already started growing. results: some of the roots seemed really big. other roots seemed normal or small. conclusion: they couldn’t tell what the effect of the compost was because the results were inconsistent. what is the dependent variable in this experiment? what is the independent variable in this experiment?

From the scenario given in this question, we can conclude that the DEPENDENT VARIABLE IS THE DEVELOPMENT OF THE ROOT CROPS, that is, how big or small they are, while the INDEPENDENT VARIABLE IS THE COMPOSTS USED.

A dependent variable is a variable whose value depend on the value of independent variable,  it is the variable that the researcher is interested in. In the question given here, the scientists are interested in the development of the root crops.

An independent variable is the variable that the researcher changed or controlled. A change in independent variable cause a corresponding change in dependent variable. In this question, the scientists changed the type of compost used and the type of compost used in turn determine how big or small the root crops turn out to be.

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]

the elements of art are the visual tools that the artist uses to create a composition. these are line, shape, color, value, form, texture, and space.

the principles of art and design are balance, contrast, emphasis, movement, pattern, rhythm, and unity/variety.