Scelta multiplaSingle-celled prokaryotes had Earth to themselves for approximately __________. 2016views
Scelta multiplaYou are watching a movie in which one of the characters excitedly claims to have found human remains in Asia dated at 10 million years old. The date was obtained by carbon-14 dating. What is your reaction? 2186views
Scelta multiplaWhat evidence most strongly suggests that an impact by an asteroid or meteorite may have caused the extinction of the dinosaurs? 2810views
Scelta multiplaThe early atmosphere on Earth is thought to have lacked which of the following gases? 2226views
Scelta multiplaMany researchers now believe that the first self-replicating molecules were __________. 2371views
Scelta multiplaWhat were the two major "problems" that had to be solved before plants, animals, and fungi could fully move into terrestrial habitats? 1719views
Scelta multiplaIn the species selection model, __________ is to macroevolution as __________ is to microevolution. 2041views
Scelta multiplaAlthough they originated around 180 million years ago, mammals underwent an adaptive radiation starting approximately 65 million years ago. Why? 2689views
Scelta multiplaAbiotically produced vesicles display which of the following rudimentary qualities necessary for life? 1719views
Scelta multiplaWhat evidence supports the hypothesis that mitochondria and plastids evolved from prokaryotic endosymbionts? 2456views
Scelta multiplaThe Miller and Urey abiotic synthesis experiment (and subsequent, similar experiments) showed that __________. 1953views
Scelta multiplaWhat prokaryotic adaptation occurred during the oxygen revolution and opened up the possibility for energy-demanding multicellular life-forms? 1778views