Which of these statements describes a limitation of the antarctic treaty system? a. it does nothing to protect scientists working in antarctica. b. it lacks references to mineral resources. c. it lacks a plan for proper waste disposal. d. it does nothing to protect the atmosphere over antarctica.

Salmonella typhimurium is a food-borne bacterial pathogen that can cause severe gastrointestinal disease. salmonella is often phagocytosed by macrophages that normally destroy bacterial pathogens, but this bacterium is somehow able to prevent the complete maturation of phagolysosomes. salmonella is able to tolerate the low ph of phagolysosomes, and in fact responds to the drop in ph by secreting toxins that interfere with other cellular responses. which of the following differences would you expect to contribute to the survival of a bacterium within an salmonella-containing phagosome, compared to a healthy phagolysosome? decreased activity of acid hydrolases increased activity of acid hydrolases decreased import of h+ ions increased import of h+ ions my guess is decreased activity of acid hydrolases but i'm not sure.

Explain the source of radioactivity in uranium in earth’s crust by which it produces nuclear radiation

9. the history of life on earth is recorded in