Cell Biology
Topic and Scope: The relationship between cell biology (cytology) and biochemistry; specifically, how the two disciplines have affected each other over the last century.
Purpose and Main Idea: The author’s purpose is to describe and evaluate the historical interaction between cell biology and biochemistry. The author’s main idea is to argue that the interaction between these two disciplines has lead to progress in both of them.
Paragraph Structure: ¶1 notes that two scientific disciplines concerned with the same general topic are often in conflict with each other in their early stages of development because of their different approaches to the topic. One discipline takes a “macro” approach to the topic, while the other discipline takes a “micro” approach.
¶s 2 and 3 go on to describe a particular historical case of conflict between two related scientific disciplines: cell biology and biochemistry. ¶4 explains that the claims of both disciplines have essentially been borne out, leading to a synthesis of the two in the form of the new discipline of molecular genetics.
¶5 summarizes the author’s main idea: competition between these related scientific disciplines has been useful, for it has generated important scientific discoveries.
The Big Picture:
• Whenever a passage compares/contrasts entities—as this passage does—make sure that you can distinguish between (among) the entities. The questions will certainly test if you can tell them apart.
• Don’t let unfamiliar scientific terms or concepts throw you. As you read, boil a science passage’s ideas down to their essence. If you simplify things as you go, the questions will be much less intimidating.
The Questions:
1. Which one of the following best states the central idea of the passage?
(A) Antithetical scientific disciplines can both stimulate and hinder one another’s research in complex ways.
(B) Antithetical scientific disciplines often interact with one another in ways that can be highly useful.
(C) As disciplines such as cytology and biochemistry advance, their interaction necessarily leads to a synthesis of their approaches.
(D) Cell research in the late nineteenth century was plagued by disagreements between cytologists and biochemists.
(E) In the late nineteenth century, cytologists and biochemists made many valuable discoveries that advanced scientific understanding of the cell.
(B) After reviewing (in ¶s 1-3) the process by which related scientific disciplines interact, ¶s 4 and 5 go on to argue that this interaction is often scientifically beneficial.
(A) Neither the author’s general discussion of the interaction between related scientific disciplines nor his specific example of the interaction between cell biology and biochemistry suggests that this interaction has negative consequences for the advancement of science.
(C) The author doesn’t go so far as to contend that the interaction between related disciplines necessarily leads to a synthesis of their approaches in all cases. After all, he only looks at one case.
(D) This choice focuses on details in ¶s 2 and 3.
(E) This choice focuses on a detail in ¶5.
• In “global” questions, watch out for choices that focus on one part of the passage rather than on the entire passage.
2. The passage states that in the late nineteenth century cytologists deduced the
(A) maps of chromosomes
(B) chemical nature of protoplasm
(C) spatial relationship of molecules within the cell
(D) role of enzymes in biological processes
(E) sequence of the movement of chromosomes during cell division
(E) This choice nicely paraphrases lines 19-21.
(A) Line 39 mentions “chromosome mapping,” but suggests that this may not have been a late nineteenth-century development. Moreover, it’s not clear whether cytologists or biochemists did the mapping.
(B) and (D) According to lines 29-32, late nineteenth-century biochemists, not cytologists, were concerned with the “chemical nature of protoplasm” (B) and the “role of enzymes in biological processes” (D).
(C) According to ¶4, biochemists, not cytologists, deal with the “spatial relationship of molecules within the cell.” Moreover, this issue has been the focus of post-1950 biochemists.
• This question illustrates the importance of checking back with the passage about details. All of the choices might have looked very tempting if you didn’t consult ¶s 2-4.
3. It can be inferred from the passage that in the late nineteenth century the debate over the structural nature of protoplasm (Highlighted) was most likely carried on
(A) among cytologists
(B) among biochemists
(C) between cytologists and biochemists
(D) between cytologists and geneticists
(E) between biochemists and geneticists
(A) If biochemists “stood apart” from the late nineteenth-century debate about the structural nature of protoplasm (as lines 25-29 say), then it stands to reason that the debate must have taken place among cytologists.
(B), (C), (E) Again, lines 25-29 say that late nineteenth-century biochemists avoided “the debate over the structural nature of protoplasm.”
(D) is out for the simple reason that the passage never even mentions “geneticists,” let alone late nineteenth-century geneticists.
• Sometimes questions can be answered through a process of elimination. If it wasn’t immediately clear to you that the debate took place among cytologists, you could have eliminated choices (B)-(E) by recognizing that neither biochemists nor geneticists were involved in the debate.
4. According to the passage, cytologists in the late nineteenth century were critical of the cell research of biochemists because cytologists believed that
(A) the methods of biochemistry were inadequate to account for all of the chemical reactions that occurred in cytological preparations
(B) the methods of biochemistry could not adequately discover and explain the structures of living cells
(C) biochemists were not interested in the nature of protoplasm
(D) biochemists were not interested in cell division
(E) biochemists were too ignorant of cytology to understand the basic processes of the cell
(B) This choice nicely paraphrases lines 35-37.
(A) The chemical reactions that occur in cytological preparations (lines 23-24) were an issue raised by late nineteenth-century biochemists, not late nineteenth-century cytologists.
(C) According to lines 29-31, late nineteenth-century biochemists were interested in the “nature of protoplasm.”
(D) The only mention of “cell division” occurs in lines 20-21, and this reference has nothing to do with the criticism of late nineteenth-century biochemists leveled by late nineteenth-century cytologists.
(E) Late nineteenth-century cytologists criticized the methods, not the knowledge, of late nineteenth-century biochemists.
• A common “trap” choice is the answer choice that uses the passage’s language but distorts the passage’s ideas. Such choices are especially common in science passages, which often contain complex language and unfamiliar terminology.
5. The author quotes Fruton (Highlighted) primarily in order to
(A) restate the author’s own conclusions
(B) provide new evidence about the relationship of cytology to biochemistry
(C) summarize the position of the biochemists described in the passage
(D) illustrate the difficulties encountered in the synthesis of disciplines
(E) emphasize the ascendancy of the theories of biochemists over those of cytologists
(A) The first sentence of ¶5 contains the author’s main idea: “[The] interaction between paired disciplines can have important [scientific] results.” A few lines later, the author quotes a similar remark by Fruton. The author, in other words, quotes Fruton in order to reinforce the author’s own conclusion.
(B), (C), (E) Fruton’s remark is general in nature; it doesn’t refer specifically to cytology or biochemistry.
(D) Like the author, Fruton believes that competition between disciplines generates progress, not problems.
• Wrong choices are often wrong for the same reason. In this case, note that choices (B), (C), and (E) all incorrectly claim that Fruton’s remark applies to the specific case of cytology and biochemistry.
6. Which one of the following inferences about when the enzyme theory of life was formulated can be drawn from the passage?
(A) The theory was formulated before the appearance of molecular biology.
(B) The theory was formulated before the initial discovery of cell architecture.
(C) The theory was formulated after the completion of chromosome mapping.
(D) The theory was formulated after a synthesis of the ideas of cytologists and biochemists had occurred.
(E) The theory was formulated at the same time as the beginning of the debate over the nature of protoplasm.
(A) ¶2 indicates that the enzyme theory emerged in the late nineteenth century, while ¶4 indicates that the discipline of molecular biology is mainly a post-1950 phenomenon. In other words, the enzyme theory appeared before molecular biology.
(B) According to ¶2, the initial discovery of cell architecture, like the formulation of the enzyme theory, occurred in the late nineteenth century.
(C) ¶3 suggests that chromosome mapping may have occurred later than the late nineteenth century. In any case, it certainly didn’t occur before the late nineteenth century.
(D) The synthesis of ideas between cytologists and biochemists is another post-1950 phenomenon.
(E) Lines 25-32 suggest that the debate about the nature of protoplasm emerged before the enzyme theory.
• The correct answers to “inference” questions stick closely to the spirit of the text. If you have to go through an intricate reasoning process in order to justify a choice, you’ve probably picked an incorrect choice.
7. Which one of the following statements about cells is most compatible with the views of late nineteenth-century biochemists as those views are described in the passage?
(A) The secret of cell function resides in the structure of the cell.
(B) Only by discovering the chemical composition of protoplasm can the processes of the cell be understood.
(C) Scientific knowledge about the chemical composition of the cell can help to explain behavioral patterns in organisms.
(D) The most important issue to be resolved with regard to the cell is determining the physical characteristics of protoplasm.
(E) The methods of chemistry must be supplemented before a full account of the cell’s structures can be made.
(B) Lines 29-31 state that late nineteenth-century biochemists were concerned with the chemical nature of protoplasm. Hence, it’s inferable that they considered understanding the nature of protoplasm to be vital to understanding cell processes.
(A) and (D) Late nineteenth-century cytologists, not late nineteenth-century biochemists, were concerned with the structure of the cell (A) and the physical traits of protoplasm (D).
(C) and (E) are beyond the scope of the passage. There’s no mention of what late nineteenthcentury biochemists may have thought about the “behavioral patterns of organisms” (C). Nor is there any discussion about whether they thought chemistry was inadequate for the task of understanding the cell (E).
• It’s important to read the question stem carefully. This particular question asks about the views of biochemists, not cytologists. If you missed this point because you read the stem too quickly, you might have fallen for wrong choice (A) or (D).
8. Which one of the following best describes the organization of the material presented in the passage?
(A) An account of a process is given, and then the reason for its occurrence is stated.
(B) A set of examples is provided and then a conclusion is drawn from them.
(C) A general proposition is stated, and then an example is given.
(D) A statement of principles is made, and then a rationale for them is debated.
(E) A problem is analyzed, and then a possible solution is discussed.
(C) ¶1 presents a general proposition regarding the relationship between two similar scientific disciplines. The rest of the passage illustrates this proposition through an extended example: the relationship between cytology and biochemistry as it has developed over the last century.
(A) What process? What reason for its occurrence?
(B) What set of examples? Only one example—the relationship between cytology and biochemistry—is explored.
(D) What statement of principles? What rationale?
(E) What problem? What solution?
• Questions with abstractly-worded answer choices aren’t necessarily more difficult than questions with concretely-worded answer choices. Don’t sacrifice an easy point out of an irrational fear of abstract language.