most of the answers are on here https://quizlet.com/78911237/bio-test-on-the-cell-membrane-osmosis-and-diffusion-8b-flash-cards/ just scroll down!!
Well, first off the spongy mesophyll does have some chloroplasts, however they are located quite far from the surface of the leaf where most of the chloroplasts are. Therefore they don't get much light and don't contribute a lot to photosynthesis in the leaf. So why should the leaf waste the energy in making chloroplasts if there is not enough light to make them all efficient enough at photosynthesis?
The polluted bacteria and algae interacts with fish and other aquatic wildlife, so they will be negatively impacted by that relationship in this case.