As part of the nitrogen cycle, bacteria convert certain nitrogen-containing molecules from one type to another. Which stage of the nitrogen cycle does the arrow in the image represent?
A. Nitrogen fixation, in which nitrogen is sunk into the terrestrial reservoir.
B. Nitrification, in which nitrogen is sunk into the atmosphere.
C. Denitrification, in which nitrogen is sunk into the atmosphere.
D. Ammonification, in which nitrogen is sunk into the terrestrial reservoir.

Which events are likely to be catastrophic to an ecosystem? select the three correct answers.a-hurricane.b-steady population growth.c-seasonal flooding.d-introducing of an aggressive invasive species.e-tsunami.

The tasmanian devil, a marsupial carnivore, is facing extinction due to devil facial tumor disease (dftd) which causes bulging cancerous lumps and lesions to erupt around the face and neck — often causing enough deformation to make seeing or eating difficult. dftd has evolved into a contagious cancer, a trait that is unique among cancers. devil mating behavior involves biting around the head and neck, allowing cells from one individual — especially cells from the crumbly dftd tumors — to be transferred to the wounds or face of a new individual. this marsupial was once found across australia, but sea levels rose, isolating the tasmanian population, while the australian population went extinct. what would be an outcome of genetic isolation that is likely to have impacted the spread of dftd? a) reduced territory puts diseased individuals in greater contact with non-diseased ones. b) inbreeding results in less variation in facial features so the cancer is generally fatal. c) genetic isolation has made it difficult for scientists to develop a vaccine against dftd. d) the lack of genetic variation in the immune system of tasmanian devils minimizes resistance to the disease.

What's wrong with this ecological pyramid? (multiple choice)1. secondary consumers should be at the bottom of the pyramid2. the sun has an arrow leading to decomposers 3. primary consumers should come after the sun4. energy retained should increase from the bottom to the top5. the sun should be at the bottom of the pyramid