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.
Water, carbon dioxide, and oxygen are among the few simple molecules that can cross the cell membrane by diffusion (or a type of diffusion known as osmosis). Diffusion is one principle method of movement of substances within cells, as well as the method for essential small molecules to cross the cell membrane.Gas exchange in gills and lungs operates by this process.n the case of active transport, the proteins are having to move against the concentration gradient. For example the sodium-potassium pump in nerve cells. Na+ is maintained at low concentrations inside the cell and K+ is at higher concentrations.