Which of these is an example of bioaccumulation?

a. an increased growth in microorganisms results in oxygen depletion .
b. the mercury contained in fish builds up on animals that eat the fish.
c. there are millions of cholera cases per year due to contaminated water.
d. materials that contain metal are toxic to organisms that live in them.

Which sentence best expresses the differing opinions of these two book reviews?

Read the following scenario to answer the following question. in some zoos, rare crosses between a male lion and a female tiger have produced hybrid offspring called "ligers." male ligers are sterile but some female ligers are fertile. in the wild, lion and tiger ranges do not naturally overlap, making such a cross unlikely. furthermore, the solitary behavior of tigers and the social organizations of lions create behavioral differences. applying the biological species concept, the sterility of ligers reveals that a. lions are probably a subspecies of tigers b. tigers and lions are the same species c. a new species called "ligers" is forming d. tigers and lions are separate species

'which of these statements about the scientific method is not true? all experiments must follow the same number of steps in the procedure. experiments may be repeated several times. some unexpected results can be beneficial. experimental results may or may not support the hypothesis.