Andrew was exposed to the chicken pox virus as a child. What happened to that virus after it crossed the blood-brain barrier and entered Andrew’s brain? a. Nothing happened at first, but the virus remained there and caused negative effects for Andrew as he got older. b. Nothing happened since the chicken pox virus cannot cross the blood-brain barrier. c. The glia in his brain engulfed the virus and then natural killer cells destroyed them both. d. Andrew’s natural killer cells were able to quickly destroy it.

Option A

Explanation:

When Andrew was exposed to the virus causing chicken pox he got infected and the virus crossed the blood brain barrier.

During the early stages when Andrew was a child there will be as such no effect of the virus in the brain.

During the early stage the virus will remain in the brain and cause harm in the later days when Andrew will be older.The virus can alter the brain functions such as homeostasis, blood brain barrier functions.It enters the brain while damaging the nervous system.

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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]