The energy which is transferred from sun to plants is the solar energy. The energy from plants to rodents is chemical energy which are the producers. Wolf and owl preys to rodent and to surroundings are consumers who get chemical energy. Then consumers are decayed by decomposers. They all get chemical energy for their function and survival.
The given diagram is food chain. Food chain is a sequence of populations or organisms of an ecosystem through which the food and its contained energy passes with each member becoming the food of a later membre of the sequence. The number of trophic levels in a food chain is 3-6 and in each trophic level a lot of biomass is consumed in liberating energy.
In the above food chain plants( producers) radiant light energy into chemical form. Rodents are primary consumer, owl is a secondary consumers or primary carnivores and wolf is a tertiary consumer or secondary carnivores.
Facilitated diffusion is a form of passive transport hence no energy is required by the cell. This means that while the molecules are moving down a concentration gradient – line normal diffusion – the movement of the molecules needs to be facilitated (in this case by a transmembrane protein) either because the molecule is polar and can't pass through the hydrophobic region of the cell membrane, or the molecule is too big to passively pass through the small natural pores of the cell membrane.
