Multiple ChoiceWhy is the four-stage hypothesis for the abiotic origin of life useful? 2459views1rank
Multiple ChoiceThe early atmosphere on Earth is thought to have lacked which of the following gases? 1566views
Multiple ChoiceCurrently scientists think the early atmosphere probably consisted of __________. 1091views
Multiple ChoiceThe Miller and Urey abiotic synthesis experiment (and subsequent, similar experiments) showed that __________. 1229views
Multiple ChoiceThe early atmosphere may not have been as reducing as originally postulated by Haldane, Oparin, Miller, and Urey. In light of current thinking about the composition of the early atmosphere, what is regarded as a likely place for the abiotic synthesis of organic molecules to have occurred? 1213views
Multiple ChoiceAbiotically produced vesicles display which of the following rudimentary qualities necessary for life? 1092views
Multiple ChoiceMany researchers now believe that the first self-replicating molecules were __________. 1317views
Multiple ChoiceA radioactive isotope has a half-life of 1.2 billion years. As measured by the presence of the isotope and its stable decay product, a rock originally contained 10 grams of the radioactive isotope and now contains 1.25 grams. Approximately how many years old is the rock? 1637views2rank
Multiple ChoiceYou 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? 1510views
Multiple ChoiceSingle-celled prokaryotes had Earth to themselves for approximately __________. 1323views
Multiple ChoiceThe correct order of the geologic eras, from most ancient to most recent, is __________. 1353views
Multiple ChoiceAncient cyanobacteria were very important in the history of life because they __________. 1446views
Multiple ChoiceWhat prokaryotic adaptation occurred during the oxygen revolution and opened up the possibility for energy-demanding multicellular life-forms? 1218views
Multiple ChoiceWhat evidence supports the hypothesis that mitochondria and plastids evolved from prokaryotic endosymbionts? 1992views