The nucleus intructs cells to do their activities
Ptolemy's model was Geocentric. This means that it put the earth at the center of the solar system, instead of the sun, with all celestial objects orbiting it. The first person to prove the validity of the heliocentric theory was Nicolaus Copernicus.
Selective logging—the practice of removing one or two trees and leaving the rest intact—is often considered a sustainable alternative to clear-cutting, in which a large swath of forest is cut down, leaving little behind except wood debris and a denuded landscape.