BIOGEOCHEMICAL ASSIGNMENT1. LABEL THE “CYCLES IN NATURE” DIAGRAMS

NITROGEN CYCLENITROGEN FIXATION - bacteria in soil join molecular nitrogen (N2) with hydrogen to form ammonia.AMMONIFICATION – when bacteria produce ammonia when they decompose waste products and dead

organisms NITRIFICATION – when soil bacteria change ammonia into nitrite and then into nitrateDENITRIFICATION – bacteria convert nitrogen compounds into molecular nitrogen

BIOGEOCHEMICAL QUESTIONS1. What is a biogeochemical cycle? Why are these cycles important to living organisms?

2. In terms of biogeochemical cycles, why is photosynthesis critical to the biosphere?

3. Describe at least 3 roles of plants in the water cycle.

4. What do nitrogen-fixing bacteria and lightning have in common?

5. Why is carbon critical to the biosphere?

6. Where is most of the biosphere’s carbon dioxide stored after it is released into the atmosphere?

7. Why are photosynthesis and cellular respiration often called the biotic phases of the carbon cycle?