| What is eutrophication? | too much nitrogen in a freshwater habitat |
| What do we mean by cycling when we talk about nutrients? | The nutrients pass from organism to organism |
| Which nutrients can be cycled? | carbon, nitrogen, oxygen, minerals and water |
| Where do organisms get their energy from? | photosynthesis (plants) and food (animals) |
| How do these nutrients leave living organisms and become recycled? | wastes and death |
| What are decomposers? | bacteria and fungi - the things that are doing the decomposing |
| What percentage of the air is nitrogen? | 78% |
| Where is nitrogen present? | nitrogen is present in all living things including the human body and plants |
| Nitrous oxide? | Nitrous oxide (N20) also known as laughing gas is used in hospitals and dental clinics as an anaesthetic |
| Nitric acid? | NHO3 is a strong acid often used in the production of fertilisers |
| What is nitrogen required for | making cell membranes, enzymes, hormones and DNA |
| What is nitrogen fixation? | getting nitrogen from the air to a food chain |
| What kind of organisms carry out nitrogen fixation? | n-fixing bacteria |
| Where are the 2 places that nitrogen fixation happens? | soil and legume root nodules |
| What plants have root nodules? | legumes - peas and beans |
| Why are these described as fertiliser factories? | they make nitrates (fertiliser for plants) |
| Word equation for nitrogen fixation | nitrogen gas --> ammonium compounds --> nitrates |
| What is nitrification? | getting nitrogen from a food chain back to the soil |
| What are detritivores? | organisms that break down waste - worms and woodlice |
| What are decomposers? | fungi and bacteria that convert nitrogen in protein to ammonium compounds |
| What kind of organisms carry out nitrification? | nitrifying bacteria |
| Where does nitrification happen? | soil |
| word equation for nitrification | ammonium compounds --> nitrates |
| What is denitrification? | getting nitrogen from the soil back to the air |
| What kind of organisms carry out denitrification? | denitrifying bacteria |
| Where does denitrification happen? | waterlogged soil (no oxygen) |
| word equation for denitrification | soil nitrates --> nitrogen gas |
| What is eutrophication? | too much nitrogen in a freshwater habitat |
