Figure 46.8 Why do you think the value for gross productivity of the primary producers is the same as the value for total heat and respiration (20,810 kcal/m2/yr)?
Figure 46.10 Pyramids depicting the number of organisms or biomass may be inverted, upright, or even diamond-shaped. Energy pyramids, however, are always upright. Why?
Figure 46.17 Which of the following statements about the nitrogen cycle is false?
- Ammonification converts organic nitrogenous matter from living organisms into ammonium (NH4+).
- Denitrification by bacteria converts nitrates (NO3−) to nitrogen gas (N2).
- Nitrification by bacteria converts nitrates (NO3−) to nitrites (NO2−).
- Nitrogen fixing bacteria convert nitrogen gas (N2) into organic compounds.