James was walking down the road when a large animal jumped out in front of him. James was startled and experienced a fast heart rate and heavy breathing. Which statement best describes James’s condition in such a situation? A. The adrenal gland secreted aldosterone, increasing sodium absorption, which increased the heart rate and breathing. B. The adrenal gland secreted epinephrine, increasing blood pressure, which increased the heart rate and breathing. C. The adrenal gland secreted androgens, stimulating calcium absorption, which increased the heart rate and breathing. D. The adrenal gland secreted cortisol, increasing glucose absorption, which increased the heart rate and breathing.

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.

Why do leaves change color in the fall? green pigments break down and no longer mask the color of chlorophyll. chlorophyll breaks down and no longer masks the colors of other pigments. red- and yellow-colored pigments grow and mask green-colored chlorophyll. green-colored chlorophyll breaks down and turns red and yellow.

What does polymerase chain reaction (pcr) do? o a. separates dna fragments by size o b. cuts a dna sample into fragments o c. provides an overall picture of a person's chromosomes o d. makes more copies of a sample of dna