A) There are no fossils in geological strata that are older than the Cambrian explosion. origin of fungal-plant symbioses A) 4, 3, 2, 1, 5 B) 4, 1, 2, 3, 5 C) 4, 1, 3, 2, 5 D) 4, 3, 1, 5, 2 E) 4, 3, 1, 2, 519) If it were possible to conduct sophisticated microscopic and chemical analyses of microfossils found in 3.2-billion-year-old stromatolites, then one should be surprised to observe evidence of which of the following within such microfossils? 41) Several scientific laboratories across the globe are involved in research concerning the origin of life on Earth. At the arrow labeled “III,” however, the igneous rock is about 1 million years old, and potassium-40 dating is typically used to date such rocks. 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.B) Only the fossils of microorganisms are found in geological strata older than the Cambrian explosion. Which graph below, if the results were produced abiotically, would have the greatest promise for revealing important information about the origin of Earth’s first genetic system? Note: The horizontal arrows indicate the direction of sea-floor spreading, away from the rift valley. At the arrow labeled “III,” however, the igneous rock is about 1 million years old, and potassium-40 dating is typically used to date such rocks.C) The Cambrian explosion is evidence for the instantaneous creation of life on Earth. 42) Assuming that the rate of sea-floor spreading was constant during the 1-million-year period depicted above, Earth’s magnetic field has undergone reversal at an average rate of once every A) 10,000 years. Note: The horizontal arrows indicate the direction of sea-floor spreading, away from the rift valley.D) The Cambrian explosion marks the appearance of filter-feeding animals in the fossil record. 43) Which section of sea-floor crust should have the thickest layer of overlying sediment, assuming a continuous rate of sediment deposition?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.At the arrow labeled “III,” however, the igneous rock is about 1 million years old, and potassium-40 dating is typically used to date such rocks.Note: The horizontal arrows indicate the direction of sea-floor spreading, away from the rift valley.
A) 1,400 B) 2,800 C) 11,200 D) 16,800 E) 22,90011) Which measurement(s) would help determine absolute dates by radiometric means? B) the extinction of any species adapted to intertidal and coastal habitats. D) They are found together in the same hybrid species.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?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.E) the endosymbiotic origin of mitochondria and chloroplasts.8) Several scientific laboratories across the globe are involved in research concerning the origin of life on Earth.E) It includes a series that shows the gradual change of scales into fur.14) If a fossil is encased in a stratum of sedimentary rock without any strata of igneous rock (for example, lava, volcanic ash) nearby, then it should be A) easy to determine the absolute age of the fossil, because the radioisotopes in the sediments will not have been “reset” by the heat of the igneous rocks. C) He would have placed them in more species than modern botanists do. It, and the loss of limbs by snakes, are an example of similar adaptations to a similar environment. A) species selection B) uniformitarianism C) sexual selection D) convergent evolution39) The existence of evolutionary trends, such as increasing body sizes among horse species, is evidence that A) a larger volume-to-surface area ratio is beneficial to all mammals. C) evolution always tends toward increased complexity or increased size.