BIO 182 FINAL EXAM ASU Questions With Complete Solutions

What is extinction? correct answer: The loss or death of a species What is mass extinction? correct answer: A decline in biodiversity greater than the background extinction rate What is background extinction? correct answer: Background extinction occurs when certain populations are reduced to zero because of normal environment change, emerging disease, predation pressure, or competition with another species How are mass extinctions detected and how many have been detected? correct answer: They're detected geologically, and there have been 5 detected What organisms became extinct during the Pleistocene and Cretaceous and what are possible causes for these extinctions? correct answer: Pleistocene: Wooly Mammoth, Giant Short-Faced Bear, Dire Wolf, Giant Beaver, Shasta Ground Sloth, American Lion -Could be extinct because of climate change (warmer temps), human overkill (predation), pathogens Cretaceous: Dinosaurs -Could be extinct because of asteroid (impact hypothesis) What is the evidence to support that there will be a 6th mass extinction? correct answer: Modern rates of extinction are 100 to 1000 time greater than the background rate What is overexploitation? correct answer: -Any unsustainable removal of wildlife from the natural environment by use of humans -Harvesting of organisms at rates exceeding the species ability to replace itself -The dominant threat to marine species -Overhunting What is habitat destruction? correct answer: Terrestrial Ecosystems: Conversion agriculture, logging, development and urbanization Aquatic Ecosystems: Draining and developing wetlands, damming rivers Species area curve - As the land area decreases, the number of species decreases