1. forms the pole of the spindle apparatus nuclear envelope 2. the membrane that surrounds the nucleus of the cell anaphase 3. having chromosomes that occur singly, not in matched sets or pairs homologous chromosomes 4. matched units of DNA containing genetic information furrowing 5. produces daughter cells with fewer chromosomes than the parent cell centriole 6. a system of fibers that go from one end of the cell to the other spindle apparatus 7. period of mitosis in which chromosomes move to opposite poles of the cell chromatin 8. method of cytokinesis in animals haploid 9. threadlike substance in nucleus which carries genetic information interphase 10. period when the cell is not engaged in division meiosis

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]

not only is it colder, it also becomes darker, less salty, and more dense.