Tcu Sawey 2017 Contemporary Issues In Biology Exam 4 Graded A+ 100% Verified

How does water affect our circulatory system? {Ans: humans are 55-60% water and can live days without fresh water}Who is "Ardi"? {Ans: -4.4 million year old ancestor of humans -found in ethiopia}Signs of a Pine Bark Beetle Infestation {Ans: -pitch tubes -pine bark beetle tunnels -blue stain fungus}What percent of all species that ever existed are extinct? {Ans: 99%; this number is derived from the large number of fossils found of preserved organisms no longer found on earth}How many people dont have access to clean water? {Ans: about 1 billion people do not have access to safe drinking water}Mass extinction {Ans: extinction rates rise suddenly for a "short" period of time; historically caused by natural causes}