AccelePrep for the ACT Test 2nd Edition Student Text

C HAPTER 11 | H YPER P REP S CIENCE • 223

6. (F) has an assumption as its argument, which is circular reasoning and incorrect. (G) is an argument without support in the passage. (J) is a weak argument since it is based on probability—a simple “it only had to happen once” refutes the argument. (H) is the strongest argument for countering Scientist 2 because if it were true, there might be no freezing lake at all.

POWER PRACTICE 3

1. Which of the following, if true, most strengthens Scientist 2’s argument? Ǥ Ž› ϐ‹˜‡ ’‡”…‡– ‘”‡ ‡–‡‘”• –Šƒ ‘”ƒŽ fell on Earth during the time life began. Ǥ Ž› ϐ‹˜‡ ’‡”…‡– ‘ˆ –Š‡ ‡–‡‘”‹–‡• •–—†‹‡† contained organic molecules. C. A simulation of early Earth chemistry showed the spontaneous formation of complex biomolecules. D. Meteorites containing amoebas have been found. 2. Which of the following is an assumption of Scientist 1? F. Complex life forms can develop quickly. G. Meteorites burn up as soon as they hit Earth’s atmosphere. H. There is a cause-and-effect relationship be- tween meteors falling and the origin of life. J. The changes on Earth’s surface due to the presence of life attracted meteor showers. 3. With which explanation of the similar biochemistry of all life on Earth would Scientist 1 most likely agree? A. A single chemical pathway to life exists. B. Life on Earth arose from a single source. C. Life on Earth is not varied. D. Meteors are simple.

DIRECTIONS: The passage below is followed by several items. After reading the passage, choose –Š‡ „‡•– ƒ•™‡” –‘ ‡ƒ…Š ‹–‡Ǥ ‘— ƒ› ”‡ˆ‡” –‘ –Š‡ ’ƒ••ƒ‰‡ ƒ• ‘ˆ–‡ ƒ• ‡…‡••ƒ”›Ǥ ‘— ƒ”‡ permitted the use of a calculator. Answers are ‘ ’ƒ‰‡ ͵ͳͳǤ How did life originate on planet Earth? Two opposing views are presented. Scientist 1 The idea that Earth could have given rise to life independently is mistaken. Life on this planet must have come from elsewhere for several reasons. First, complex life appears very suddenly in the geological record. Secondly, all life on Earth has a very similar biochemistry. If life originated on Earth, one would expect regional variations in biochemistry, similar to the variations in species spread over large ƒ”‡ƒ•Ǥ ‹ƒŽŽ›ǡ –Š‡ –‹‡ ™Š‡ Ž‹ˆ‡ ϐ‹”•– ƒ’’‡ƒ”‡† ‹ the geological record was also a time when large numbers of meteorites struck Earth. The meteorites must have caused life to appear on Earth. The simplest hypothesis is that the meteorites brought life with them. Scientist 2 Life need not have been imported from outer space. The chemicals required for life existed on –Š‡ •—”ˆƒ…‡ ‘ˆ ƒ”–Š ƒ– –Š‡ –‹‡ Ž‹ˆ‡ ϐ‹”•– ƒ’’‡ƒ”‡†Ǥ The fact that all life has a similar biochemistry can be explained by considering that any group of chemicals that won the race to life would probably have used the “almost-living” as food. Since we can offer explanations for what happened without relying on a meteorite of unknown composition that might have fallen to Earth, we should stick to hypotheses that have fewer unknowns.