Originally a marine species, stickleback fish now live in both marine and freshwater environments. marine sticklebacks have pelvic spines that protect them from marine predators. freshwater sticklebacks do not have pelvic spines, which reduces their likelihood of being caught by freshwater predators that can grasp onto these spines. the lack of spines in freshwater sticklebacks results from a heritable mutation that modifies the function of the pitx1gene. this mutation occurred:

a.
in the mrna that is transcribed from the pitx1 gene in pelvic cells.

b.
in the regulatory region of the pitx1 gene.

c.
in the coding region of the pitx1 gene.

d.
in the cells of the pelvis of freshwater sticklebacks.

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.

Which type of bond forms between water moleculesstrong bondhydrogen bondcovalent bondpolar bond

Which of the following terms best matches this definition: the process where humans choose the traits that will be present in the next generation through breeding. question 4 options: genetic determinism artificial selection acquired selection natural selection