What is the structure of the reef ecosystem made of?  coral skeleton fish excretion shark teeth the chloroplasts of algae

Plants require nitrogen for life 13. Plants require nitrogen for life, but only certain forms of soil nitrogen are accessible to most plants. Which forms are directly useful to plants, and from where do these come? NH4+ and NO3- from ammonification to form ammonium cations and nitrification to form nitrate anions N2 and organic nitrogen (nitrogen bound to carbon-based molecules) from denitrification to form molecular nitrogen and biosynthesis to form organic nitrogen NO2- from nitrification to form nitrite anions Nitrogen containing proteins released from dead organisms by decomposers   14. Of the following biomes, which typically receive the least amount of precipitation? tundra savannah desert deciduous forest   15. What is the structure of the reef ecosystem made of?  coral skeleton fish excretion shark teeth the chloroplasts of algae   16. Which of the following correctly identifies an abiotic factor influencing the distribution of biomes?  the amount and type of bacteria present in a given patch of soil the total number of plant-eating insects in a given space elevation of a land mass above sea level* the total number of species in a given area 18. What does the majority of climate scientists believe is the cause of the current change in climate on earth?   an enhancement of the greenhouse effect our decreased reliance on fossil fuels for energy a thinning of the ozone layer melting of the polar ice caps an increase in solar radiation   19. which of the following is NOT a result of global warming? Changes in the breeding seasons of some species. Decreasing sea levels. Melting permafrost. Shifts in the geographical range of some species.