Taxonomy is the science of classifying organisms. The system currently used by taxonomists is called the Linnaean taxonomic system, in honor of Swedish biologist Carolus Linnaeus (1707 â 1778). The Linnaean system breaks down organisms into seven major divisions, called taxa (singular: taxon).
When used by the Chinese to protect their land, this section of the wall has had many guards to defend China's capita, Beijing. Made of stone and bricks from the hills, this portion of the Great Wall is 7.8 meters (25.6 ft) high and 5 meters (16.4 ft) wide.
The Ming Dynasty was the last state to implement large-scale Great Wall construction. Sections built in that dynasty measured 5,500.3 miles (8,851.8 kilometers) long in total, with 3,889.5 miles (6,259.6 kilometers) of artificial ramparts, occupying two fifth of the whole length.