Scelta multiplaSingle-celled prokaryotes had Earth to themselves for approximately __________. 1981views
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? 2153views
Scelta multiplaWhat evidence most strongly suggests that an impact by an asteroid or meteorite may have caused the extinction of the dinosaurs? 2785views
Scelta multiplaThe early atmosphere on Earth is thought to have lacked which of the following gases? 2195views
Scelta multiplaMany researchers now believe that the first self-replicating molecules were __________. 2269views
Scelta multiplaWhat were the two major "problems" that had to be solved before plants, animals, and fungi could fully move into terrestrial habitats? 1673views
Scelta multiplaIn the species selection model, __________ is to macroevolution as __________ is to microevolution. 2020views
Scelta multiplaAlthough they originated around 180 million years ago, mammals underwent an adaptive radiation starting approximately 65 million years ago. Why? 2663views
Scelta multiplaAbiotically produced vesicles display which of the following rudimentary qualities necessary for life? 1699views
Scelta multiplaWhat evidence supports the hypothesis that mitochondria and plastids evolved from prokaryotic endosymbionts? 2438views
Scelta multiplaThe Miller and Urey abiotic synthesis experiment (and subsequent, similar experiments) showed that __________. 1915views
Scelta multiplaWhat prokaryotic adaptation occurred during the oxygen revolution and opened up the possibility for energy-demanding multicellular life-forms? 1758views