If two species of bacteria use glucose as an electron donor, but species a uses oxygen as the final electron acceptor and species b uses nitrate, then how much glucose would species b need to use to generate the same amount of atp as species a? see section 26.3 (page 526) .

Species B would need about 60% more glucose to generate the same amount of ATP as species A. This is because molecular oxygen is a highly oxidizing agent and therefore, is an excellent electron acceptor compared to other less-oxidizing substances such as sulfate, nitrate or fumarate. 

Idk

That is true tge cactus as a structural adaptation to its envirinment has it leaves reduced to spines. but this doesnt mean it cant produce food it produces food because of the presence of chlorophyll in its stem