Give three reasons
for using heat as a fixative

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.

4.06 hc)a five-year review of threats to the southern resident orca population of the united states concluded that the top threats were prey availability, contaminants, and effects from recreational and whale watching vessels. further down the list are oil spills, disease, and effects from commercial vessels not targeting whales. how might this list be different if it were for transient whale populations, which have a larger average population size and live farther offshore in open waters? a)the transient population is more likely to be affected by contaminants. b)the transient population is less likely to be affected by whale watching vessels. c)the transient population is more likely to be affected by disease. d)the transient population is less likely to be affected by prey availability.

In which situations is the principle of cross-cutting relationship useful in determining relative age?