Here's the next chapter. Writing the last one rally helped me in my physics mock :) so this one is biology based enjoy and I hope you learn something :) xx

Please review xx

Katie xx

That evening max and Zoe were sitting having dinner. Zoe was thinking about what to teach max about next. Max noticed that Zoe seemed somewhat deep in thought.

"Zoe what you thinking about?"

"Umm just about our next lesson."

"Oh, I was thinking how about some biology."

"Sounds good to me, I take it its my turn?"

"Yep. So what we gonna be leaning about."

"How much do you know about eutrophication?"

"Eutroph what?"

"Not a lot I see. Well let me explain."

"Eutrophication occurs when excess nitrogenous fertilisers get washed into rivers or lakes. This then causes an algae bloom. The algae block the light from getting to the plants below it meaning they can't photosynthesis meaning they produce no oxygen and end up dying. The decomposes then use up all the oxygen through respiration whilst breaking down the dead plants. This means that there is no oxygen for the fish to respire meaning they suffocate and die."

"That's all a bit morbid."

"It's life max, and if farmers were more careful it wouldn't get to that."

"I suppose."

"I've just had another idea I've thought of something that could link in nicely."

"What."

"The nitrogen cycle."

"The whaty what."

"Basically it is the cycle of nitrogen.

Nitrogen fixing bacteria convert atmospheric nitrogen into nitrogen compounds (nitrates). This can also occur when lighting strikes. The nitrates in the soil are taken into the plants via active transport which uses energy from respiration to draw in the nitrates against the concentration gradient. From an area of low concentration (soil) to an area of high concentration (root hair cells). When the plants die decomposer bacteria convert the dead matter into urea and ammonia. The nitrifying bacteria converts the urea and ammonia back into nitrates. And finally denitrifying bacteria convert nitrates back into atmospheric nitrogen."

"Wow, I think I've actually learnt something, better late than never I suppose. If you had been my teacher I would have been top of the class."

"Well I'm glad to hear, but I'm afraid not even in old enough to have been your teacher."

"I know but I've got you now."

"Indeed you have. Dance watching a film I've had just enough of science for one day."

"Yeah me too. What film?"

"If I stay."

"Zoe! As long as you don't cry."

"I'm not making any promises."

Please review. There'll be more soon xx

(If there's anything you would like me to write a chapter on please let me know I'll do my best ) xx