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By identifying stable isotopes of carbon-12 in human tissue, [#permalink]
14 Jul 2013, 06:20
This post was BOOKMARKED
By identifying stable isotopes of carbon-12 in human tissue, scientists have been able to prove that 25% of all carbon molecules consumed by Americans originate in corn. One of the most ubiquitous substances in the North American diet, corn has seemingly innumerable, multifarious uses. Each corn kernel’s endosperm contains a preponderance of starch, a substance made of glucose molecules connected by glycosidic bonds which create long and complex chains of carbohydrate molecules that scientists have learned to separate and rearrange to form crucial raw materials for food and other industries. In the form of cattle feed, corn provides the key ingredient in the production of cheap meat, the basis of the contemporary American diet, while high fructose corn syrup is the major component of carbonated beverages so popular in the West. It could be argued that the current American way of life is not imaginable without the abundant supply of this staple crop. Therefore, given the multitude of corn’s benefits unlocked by modern technology, it is ironic that an earlier culture equally dependent on it for sustenance might have been severely hampered by its limitations.
According to most scientists, corn is a mutated descendent of teosinte, a wild grass native to Central America. The ears of the teosinte plant were not large, encased the seeds in a hard envelope and contained much less seed than comparable grains, making them unappealing to primitive humans. However, several thousand years ago, an evolutionary jump redesigned the teosinte. The tassel, the male inflorescence at the end of a primary lateral branch of the plant, underwent a feminization which monopolized the resources of the lateral branch, creating larger ears with a corresponding number of seeds with higher nutritional content.
This evolutionary path is, according to anthropologist Jared Diamond, a key to the condition of pre-Columbian American societies. While Eurasian societies had an abundance of wild grains available for cultivation and, therefore, moved to agriculture tens of thousands of years ago, a time period which allowed for the creation of large populations and, eventually, a market for advanced technologies, pre-Columbian Americans had no enticement to form agricultural societies. They made this move relatively late and therefore had no time to create societies as large and complex as the Europeans, a fact that led to their defeat when the latter arrived in Central America.
Diamond’s argument is not only innovative and parsimonious but relies on a seemingly unassailable basis of our knowledge of the evolutionary biology of corn. However, historical considerations make one reluctant to accept the veracity of Diamond’s elegant argumentation. Whenever they started to grow, as we now know, Central American societies achieved significant demographic growth and technological progress and were able to mobilize significant resources for the conduct of war. Therefore, one must seek the roots of their defeat not in their dependence on corn but in factors such as epidemics launched by European arrival and the political dissensions in their midst.
Q1: Which of the following, if true, would weaken the author's objections to Diamond's theory? (A) Although the population of pre-Columbian America was decimated by disease, the armies arrayed against the Europeans did not suffer the same fate because they did not live in close quarters. (B) While they were outnumbered, the Europeans' use of iron breastplates allowed them to withstand the impact of bronze-tipped arrows used by pre-Columbian Americans. (C) Remains of pre-historic agricultural societies in Eurasia show evidence of sophisticated technologies at much higher levels than those achieved by American societies at that time. (D) Some societies of pre-Columbian America were strong enough to enforce their will on their neighbors and drew on those resources to present a united front against a third party. (E) The average size of a pre-Columbian American village and the average yield of its crops were only half as large as their European counterparts.[/list]
Q2: The author of the passage is mainly concerned with (A) debating the negative influence of corn's evolutionary development on the conflicts between the pre-Columbian Americans and Europeans, in contrast to corn's positive influence on our society today (B) comparing the uses of corn in the present to the use of teosinte in the past, which led pre-Columbian American societies to develop in drastically different ways from their European counterparts, possibly leading to the former's downfall (C) arguing against the theories of Jared Diamond which stipulate that corn's late evolutionary development caused Native American societies to develop later than European societies, leading to the former's downfall (D) discussing the effects of corn on both the current American society and the pre-Columbian American society, which, as Jared Diamond argues so elegantly, caused the latter's downfall in its conflict with the Europeans (E) explaining the benefits of corn's use today and explaining how the theory that corn's use by pre-Columbian American societies put them at a disadvantage in comparison to European societies is at odds with today's knowledge of the former
Q3: According to Jared Diamond, immediately after teosinte's mutation (A) pre-Columbian American societies turned to agriculture (B) its descendant was the only grain available for cultivation in the pre-Columbian Americas (C) corn did not yet possess nutritional value equivalent to those of other grains (D) pre-Columbian American societies started to cultivate corn and other wild grains (E) the disparity between pre-Columbian American and Eurasian populations was equal to the disparity between the two populations during the Europeans' arrival to the Americas
Q4: One purpose of the second paragraph is to (A) compare the uses and effects of a plant on a culture to the uses and effects, described in the first paragraph, of that plants' descendent on another culture (B) put forth a scientific fact which clarifies a statement made in the first paragraph and whose possible historical significance is presented in the third paragraph (C) explain a statement made in the first paragraph whose possible implications are detailed in the third paragraph (D) describe a scientific process whose possible implications, according to one scholar, are detailed in the third paragraph and fourth paragraphs (E) provide scientific background information that explains the topic which the author is most concerned with in the first paragraph[/list]
Whoa ! ! ! I did all wrong . . Can you provide explanations plz . .
for 1 I marked A . We need to weaken the fact that other factors were more important than corn. 1 says that the disease did not affect army, therefore it weakens other factor. B was my last choice it provides another reason for defeat and strengthens the objections against Diamonds theory
2. I marked D, there is some glitch in last part " caused latter's downfall but para mentions objections to it too" , but why A . its not a debate .
3. I marked E, because diamond assumed that the dependence on teosinte's mutation (corn) disadvantaged Americans , he believed that the situation was same immediately upon mutation and when Europeans arrived. . How can we infer that the descendant was only crop. Nothing such mentioned in para.
4. I marked D . the mutation is described as a process and implications are presented in 3rd and 4th para. How can it be B , which statement in first para is described in 2nd para. The last line of first para just states that corn had limitations what is its link with the mutation process. D seems better.
Any other explanations plz _________________
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Re: By identifying stable isotopes of carbon-12 in human tissue, [#permalink]
18 Oct 2013, 03:41
Hm, I answered D A B D. Q1 - I really first thought to answer B (correct answer), author's objection: "Central American societies achieved significant demographic growth and technological progress and were able to mobilize significant resources for the conduct of war." To weaken this, we need to prove that demographic growth wasn't enough / technological progress wasn't enough / they couldn't mobilize. A - deals with authors opinion, not objections. - pass B - proves that technological progress wasn't enough. NOTE C - to general, not clear what technologies, did it affect they encounter? - pass, B is stronger D - proves that mobilization argument is wrong. NOTE E - irrelevant. talks about general populations, it wasn't europe vs. america continent battle. Now I know why D is wrong: ................Population.. Progress ........Mobilization Diamond .......Weak .........Weak .... Weak (non-complex) Author .........Strong ......Strong ...... Weak B .................-- ........... Weak .......... -- .................. - contradicts Author, supports Diamond.w D ................ -- ............ -- ......... Strong ................. - contradicts both, supports no one.
Edit: Answer to Q4.
So, my second mistake: Second para gives us: history of corn and evolution from non-agricultural plant to agricultural (appealing). A) irrelevant. pass B) scientific fact - true, consequences in 3rd para - true, 1st para statement clarification - ??? C) explain statement if 1st para - ??? implications in 3rd - true. D) scientific process - true, Diamond - true, 3rd para - true, 4th - false (I missed this!!!), pass E) scientific topic - true, most concerned in frst para - ??? So now we have B C E, all referring to first para (B C - statement, E - most concerned) 1st para: All statements: "By identifying stable isotopes of carbon-12 in human tissue, scientists have been able to prove that 25% of all carbon molecules consumed by Americans originate in corn." One of the most ubiquitous substances in the North American diet, corn corn has seemingly innumerable, multifarious uses. Each corn kernel’s endosperm contains a preponderance of starch scientists have learned to separate and rearrange to form crucial raw materials for food and other industries In the form of cattle feed, corn provides the key ingredient in the production of cheap meat meat, the basis of the contemporary American diet high fructose corn syrup is the major component of carbonated beverages so popular in the West the current American way of life is not imaginable without the abundant supply of this staple crop. "an earlier culture equally dependent on it for sustenance might have been severely hampered by its limitations." Now, para2 doesn't provide explanation for hampering earlier culture by corn's limitations, though it explains this limitations to some extent. hence C and E are wrong. B - ok, this seem to work because it uses the word "clarification", it doesn't explain the statement, but it clarifies what kind of limitations we are talking about.
I missed that (totally) and I missed false statement about para.4 in D. I just thought, "well this paragraph explains nothing from para1, so D should be closer", I missed "clarification". _________________
By identifying stable isotopes of carbon-12 in human tissue, [#permalink]
31 Aug 2015, 06:06
This post was BOOKMARKED
Q1. I marked (C)
My (incorrect) reasoning runs as follows: Given evidence of the sophisticated technologies available to Eurasia, the fact that they won is not surprising and is in line with what Diamond has stated (which weakens the author's position that Americans did indeed have comparable tech).
Looks like the mention of "pre-historic" as against "pre-Columbian" the only problem in (C)? Is anyone able to validate?
Q2. I marked (C)
It's incorrect, apparently, but I am still convinced it is the right option. Comments, anyone?
Q3. I marked (E)
Isn't it a bit far-fetched to go from "no enticement" to "only grain available"? Or does "no enticement" automatically signify that there was absolutely no other crop available?
Since the test is adaptive, I also got another question -
Which of the following is not mentioned in the passage about teosinte? (A)Because it had fewer overall seeds than similar grains and the small seeds it did have were covered by a hard shell, teosinte was inedible to primitive humans. (B)After a part of the teosinte plant underwent a drastic genetic change, it absorbed most of the nutrients gathered by the branch to which it was attached. (C)An evolutionary jump changed teosinte's small ears into larger ones with higher nutritional value, setting it on the path to becoming what we now know as corn. (D)When the teosinte's male inflorescence at the end of a branch began to consume all the available resources of that branch, the resulting ears became better for human consumption. (E)The change in teosinte's tassel, which created ears more beneficial to humans, played a central role, in Jared Diamond's opinion, in the fate of pre-Columbian American societies.