With one gene controlling a trait we have three possible genotypes, AA, Aa and aa and depending on the allelic interactions (dominance or incomplete dominance) we can have two or three phenotypes. As more and more genes control a trait, a greater number of genotypes are possible. The formula that predicts the number of genotypes from the number of genes is 3 to the power n. (n is the number of genes.) The following is the number of genotypes for a selected number (n) of genes which control an arbitrary trait.
Coal-Powered Electric Cars Out-Pollute Fossil Fuels. by. If the energy used to power electric vehicles comes from traditional resources such as burning coal rather than renewable sources, driving battery-powered cars will pollute the air more than cars powered by fossil fuels.
Coal combustion is generally more carbon intensive than burning natural gas or petroleum for electricity. Although coal accounts for about 77 percent of CO2 emissions from the sector, it represents about 39 percent of the electricity generated in the United States.