Amino acid dating fossils
Amino acid dating fossils
A) the accumulation of the daughter isotope B) the loss of parent isotopes C) the loss of daughter isotopes D) Three of the responses above are correct. C) an overall decrease in the surface area located in the continental interior. E) They have the same function.37) Many species of snakes lay eggs. E) directed selection.38) In the 5-7 million years that the hominid lineage has been diverging from its common ancestor with the great apes, dozens of hominid species have arisen, often with several species coexisting in time and space.
B) change the atmosphere from oxidizing to reducing. D) cause iron in ocean water and terrestrial rocks to rust (oxidize). E) Its Hox genes cooperate to bring about sexual maturity at the proper stage of development.30) Bagworm moth caterpillars feed on evergreens and carry a silken case or bag around with them in which they eventually pupate. C) the earliest reptiles could fly, and the feathers of flightless dinosaurs were vestigial flight surfaces.
E) Recent evidence supports the contention that the Cambrian explosion may not have been as “explosive” as was once thought.18) What is thought to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth? A) A B) B C) C D) D E) E The figure represents a cross section of the sea floor through a mid-ocean rift valley, with alternating patches of black and white indicating sea floor with reversed magnetic polarities.
At the arrow labeled “I” (the rift valley), the igneous rock of the sea floor is so young that it can be accurately dated using carbon-14 dating.
D) Early Earth’s atmosphere had significant quantities of ozone.3) What is true of the amino acids that might have been delivered to Earth within carbonaceous chondrites?
A) They had the same proportion of L and D isomers as Earth does today. formation of DNA-based genetic systems A) I, II, III, IV B) I, III, II, IV C) II, III, I, IV D) II, III, IV, I5) Which of the following is a defining characteristic that all protobionts had in common?
uncertainty about which gases comprised early Earth’s atmosphere A) 1 only B) 2 only C) 1 and 2 D) 1 and 3 E) 2 and 32) How were conditions on the early Earth of more than 3 billion years ago different from those on today’s Earth?
A) Only early Earth was intensely bombarded by large space debris. C) Less ultraviolet radiation penetrated early Earth’s atmosphere.
Which of these questions is currently the most problematic and would have the greatest impact on our understanding if we were able to answer it?
A) How can amino acids, simple sugars, and nucleotides be synthesized abiotically? C) How did RNA sequences come to carry the code for amino acid sequences?
B) Their abundance would have been dramatically reduced upon passage through early Earth’s oxidizing atmosphere. A) the ability to synthesize enzymes B) a surrounding membrane or membrane-like structure C) RNA genes D) the ability to replicate RNA6) The first genes on Earth were probably A) DNA produced by reverse transcriptasefrom abiotically produced RNA.
C) There were more kinds of amino acids on the chondrites than are found in living organisms today. B) DNA molecules whose information was transcribed to RNA and later translated in polypeptides. D) oligopeptides located within protobionts.7) The synthesis of new DNA requires the prior existence of oligonucleotides to serve as primers. This latter observation is evidence in support of the hypothesized existence of A) a snowball Earth.
D) They were delivered in the form of polypeptides.4) Which of the following is the correct sequence of events in the origin of life? B) earlier genetic systems than those based on DNA. D) the delivery of organic matter to Earth by meteors and comets.