Energy in an ecosystem flows directly from a. producers to tertiary consumers b. producers to secondary consumers c. tertiary consumers to secondary consumers d. secondary consumers to tertiary consumers

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

The first amino acid of a new polypeptide chain is

Eutrophication caused by human nutrient pollution.