Biol 322 Exam 4 (Ch. 11-15, 18, 19, 20) Questions and Correct Answers

Among the oldest fossils on Earth are the microfossils from the Agnes gold mines of South Africa, which are ______ years old 3.2 billion In order to understand the origin of life on Earth, evolutionary biologists collaborate with: All of the above (chemists, geologists, atmosphere scientists) Which of the following statements about LUCA is NOT correct? It is meant to be a single organism Which two scientists elaborated on Darwin's idea of the "warm little pond" and formulated the "prebiotic soup hypothesis" as the first hypothesis for the abiotic origin of life on earth? Oparin and Haldane Which gas was most likely the least abundant in early Earth's atmosphere? oxygen Miller and Urey developed and conducted some experimental tests for a "prebiotic soup" model of the origin of life, which had been proposed a few decades earlier by Oparin and Haldane. What did Miller and Urey show could be synthesized abiotically? amino acids In 1977 Sidney Fox tried a different approach to testing the prebiotic synthesis of biological molecules. He mixed a number of different amino acids together at a high temperature (120 C) in an environment lacking water. When he subsequently placed the mixture into water to investigate what the amino acids would form he: found some peptide-like structures, but the bonds between the amino acids were weak and unstable The first genetic material was most likely: RNA All of the following is true regarding Spiegelman's experiment on the origins of life EXCEPT that: there was no selection for any of the variations in length Which of the following statements about the Lincoln and Joyce experiment on self-replicating ribozymes is most likely correct? The self-replicating ribozymes that had more efficient catalytic activities would soon began to dominate their populations What is the most relevant hypothesis for the benefit of making the switch from the RNA- to a DNA-based genetic system during the evolution of life? DNA is a more stable molecule because deoxyribose is less reactive than is ribose