A bacterial culture is being tested for its ability to reduce nitrate. After incubation and growth of the bacteria in nitrate broth, there is no accumulation of gas in the Durham tube. The test for the presence of nitrite is colorless. When zinc powder is added, a bright red color develops. Interpret these results.

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.

The following hormone had their receptors in the cell membrane except a-insulin b-tsh c-gh d- cortisol

Dan made the table shown to describe two different relationships between animals. organism interactions relationship a relationship b one organism lives inside the organism it feeds off no organism is harmed which of the following statements is most likely correct?