Passive diffusion is a form of passive transport and a type of diffusion by which particles from a high concentration gradient passes through a biological membrane to a low concentration gradient. Diffusion, or simple diffusion on the other hand, is the passage of molecules without the need of a membrane.
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.
Cutting down trees results in loss of habitat for many animals in the wild, because over 70% of animals that live on land live in trees! Cutting down trees can also reduce our oxygen.
