12) biological nitrogen fixation is accomplished byA) protozoans.b) bacteria.c) fungi.d) plants.Answer: bTopic: Section 23.813) The largest pool of nitrogen is
15) global estimates of denitrification in terrestrial ecosystems vary widely but are of the order 200k1012 g/yr4 and more than half of that total occurs in wetland ecosystems. if restoration results in an increase in wetland area by approximately 25E4 it would be expectedthat losses of nitrogen through denitrification would be closer to 6) which of the following nutrients has a cycle that does not contain an appreciable atmospheric phase?17) The ma9or process regulating phosphorus availability for net primary production is the internal cycling of phosphorus from A) organic to inorganic forms.b) inorganic to organic formsc) atmospheric fixation.d) rock weathering.Answer: ATopic: Section 23.918) hydrogen sulfide is transformed into sulfate or elemental sulfur by19) which of the following represents the largest anthropogenic source of sulfur released to the atmosphere?
2c) which of the following cycles is thought to be most under biological control?True or false Questions1) without the cycling of water4 biogeochemical cycles would cease.Answer: TRUETopic: Section 23.12) Soil formation and soil characteristics have ma9or influence on the processes of nutrient retention and release. Answer: TRUETopic: Section 23.23) flowing water aquatic systems Bstreams and rivers) contain high levels of organic matter so are rarely dependent on inputs from terrestrial system. Answer: FALSETopic: Section 23.2&) precipitation can be a significant input of nutrients in ecosystems.Answer: TRUETopic: Section 23.25) The biogeochemical cycles of one ecosystem are typically independent from those of otherecosystems.Answer: FALSETopic: Sections 23.& and 23.136) carbon cycles more quickly through cold and dry ecosystems than it does through warm and wet ecosystems.Answer: FALSETopic: Section 23.57) fossil fuels develop as a result of complete decomposition of organic matter in swamps andmarshes.
- One '16
- jane stone