Help needed ASAP please help

Look at the figure above. which atmospheric layer has around 80 percent of the mass of the earth's atmosphere? (hint: it's where the clouds seen on earth are formed.) a. exosphere b. troposphere c. stratosphere d. thermosphere

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 accompanying figure shows the percent of selected dna sequences that match between a chimpanzee and other primates. these data support the hypothesis that the figure shows the percentage of selected d n a sequences that match between the chimpanzee and other primates. the human has an almost 98 percent match, the gorilla has an almost 97 percent match, the orangutan has a 96 percent match, the gibbon has an almost 95 percent match, and the old world monkey has an almost 92 percent match. the accompanying figure shows the percent of selected dna sequences that match between a chimpanzee and other primates. these data support the hypothesis that the figure shows the percentage of selected d n a sequences that match between the chimpanzee and other primates. the human has an almost 98 percent match, the gorilla has an almost 97 percent match, the orangutan has a 96 percent match, the gibbon has an almost 95 percent match, and the old world monkey has an almost 92 percent match. chimpanzees and gibbons are the most closely related the chimpanzee's closest surviving relative is humans orangutans are the primates least closely related to chimpanzees old world monkeys and gibbons are the most closely related