The answer is : Thermosphere. At this point the homosphere (troposphere, stratosphere and mesosphere) ends at about 80 km from the surface, gas molecules<span> are here</span>bombarded<span> by X-</span>rays from the sun<span> and subsequently form the ionosphere.
Hope this helps! :)</span>
The correct answer is electrons.
Electron transport chain refers to an array of complexes, which mediates electrons from electron donors to electron acceptors through redox reactions, and combines the transfer of electrons with the transfer of protons through a membrane.
This produces an electrochemical proton gradient, which instigates the production of ATP. The ultimate electron acceptor in the electron transport chain is oxygen in aerobic respiration and sulfate in anaerobic respiration.
The answer is plants. Plants are at the start of the food chain :)
