If the same base pairs are used to code for all organisms , why is there so much variation amoung organisms

What season is it in the southern hemisphere when it’s december? a) fall b) spring c) winter d) summer

Religious conflict in northern ireland started with a) cultural differences resulting from viking invasions around 800 b) england’s split from the catholic church in the 1500s c) rebellions in ireland between 1916 and 1921 d) the norman invasion of england in 1066

Which layer surrounds the center of the earth? a: crust b: core c: mantle