Ceres: The largest object that orbits in between Mars and Jupiter in the asteroid belt, Ceres has an average orbital speed of 17.822 kilometers per second. It was discovered in 1801 by the Italian monk and astronomer Giuseppe Piazzi. In 2006, Ceres was classified as a dwarf planet.
Diffusion is the net passive movement of particles (atoms, ions or. molecules) from a region in which they are in higher concentration to. regions of lower concentration. It continues until the concentration of. substances is uniform throughout. Some major examples of diffusion in biology: â¢ Gas exchange at the alveoli â oxygen from air to blood, carbon. dioxide from blood to air. â¢ Gas exchange for photosynthesis â carbon dioxide from air to. leaf, oxygen from leaf to air.
Quick Answer. Gaseous exchange occurs in the alveoli by simple diffusion. The blood flowing past the alveoli is rich in carbon dioxide and very poor in oxygen. The gas molecules naturally flow in the direction of lower concentration through the thin gas exchange membrane, which is only two cells thick.