Think of the Conflicting Viewpoints Passages as a debate: two or more parties state their conflicting beliefs. Sometimes they agree on one point, but disagree on others.

There will only be one Conflicting Viewpoints Passage on the ACT Science section. It can appear at any point throughout ACT Science.

For the most part, you’ll know it when you see it. It’s the one that doesn’t really contain any tables, graphs, or figures. Occasionally, there might be a table or graph in the answer choices, but nothing in the passage itself.

In every other type of passage, you don’t give a darn what’s going on. You don’t need to understand the big picture at all. It’s almost always irrelevant. But on these passages, the big picture is essential. There’s no quick graph, or table, or easily identifiable bit of data, that you can immediately scan and reference. So you have to have some clue of what’s going on before you ever take a crack at the questions. Otherwise, you’ll just end up reading everything anyway.

For these passages, you have a slightly different checklist that you’re going to follow:

1. Rapidly read the entire passage and craft a mental table of contents. You don’t need to remember any specific details, numbers, equations, etc. All you need to know is what the passages are talking about in general.
2. Express the “main idea” of what’s going on. Just state the main idea or topic of what the passage speaks about. Depending on the passage, this could be as simple as: “Three dudes talk about why dinosaurs died” or “Four guys try to explain why formaldehyde is produced from a certain chemical reaction.” Just a very simple summary will do.
3. For each dude in the passage, figure with his “take on the issue” is. I cannot express how important this is to do. The point of these passages is always that some ‘dude’ that is the “scientist 1” and “scientist 2” or “Researcher 1,” or “Researcher 2” agree or disagree about a certain theory, or an element of it. The more you can simplify their overall take on things, the easier every single question will be to answer.

For instance, my notes for a particular passage would be as simple as:

• Scientist 1: Stars -> 20 Mm big on their own. Then they need to merge to get bigger.
• Scientist 2: Stars -> 40Ms big on their own. Then they need to merge to get bigger.
• Scientist 3: Mergers ain’t so likely. Stars can get as big as they want on their own.

As you can see, this isn’t Shakespeare. It is just the simplest summary of the ‘dude’ idea on the main idea of the passage at hand. By labeling these things so simply, I’ll be able to answer basically every question without having to do any additional research! I basically don’t even need to read this passage anymore.

4. For the questions, make sure you are considering the right point of view. On these problems, you need to make extra sure that you’re focusing on the right dude.
   If it asks about Scientist 1, make sure you are looking at Scientist 1’s paragraph. The ACT will always have an answer choice with Scientist 2’s point of view, hoping that someone will fall for that incorrect answer.
   This is especially important on the Conflicting Viewpoints questions that ask, “Which of the following would support Student 1, but not Student 2?” You should circle and/or underline the Student you are looking to support, in this case, Student 1. Put an X through the Student you are not looking to support like:

Which of the following would support Student 1, but not Student 2?

Few additional points to remember when attacking the conflicting viewpoint questions:

1. Some questions will ask you to just relay facts you read in the passage. This question just requires you to go back and look at the paragraph in question. These questions are easy, but it is also easy to make a careless mistake on these questions.
2. Some questions simply ask you to restate the information stated in both viewpoints. For example, if a question asks DNA Hypothesis and Protein Hypothesis both agree that:

A. DNA is less abundant than proteins

B. DNA is found throughout the nucleus and cytoplasm

C. Protein is found only in the cell’s nucleus

D. Genes are made up only of DNA

The question asks us to find the statement that both DNA and Protein Hypothesis would agree with. To do this, you need to use process of elimination. Look at each point and ensure its stated in both the hypothesis. If it is stated on only one, eliminate that option.

3. Ignore the validity of the viewpoint. Sometimes one viewpoint will be factually false and you will know it from your previous science studies. Ignore it! You still need to understand the viewpoint and be able to answer questions about it.

EXAMPLE 1:

A teacher in a chemistry class placed two beakers with pure water inside of a fume hood. The teacher added a small quantity of salt to one of the beakers and stirred the solution until the salt solute was completely dissolved. Then, the teacher added an unknown solid metal to the solutions. The metal reacted heavily with the salty water, causing a spark, but did not react with the pure water.

The teacher asked three students to explain what had occurred.

Student I

The metal has a rough surface that produced friction with the salts in the water. Once the metal touched the salt particles, heat was generated from the frictional force between the metallic surface and the salts. It was this heat which caused the spark in the water. The salts, therefore, must have also contained a rough surface to produce the proper amount of friction. Without any salts present in the pure water, there were no particles available to produce friction with the metallic surface.

Student 2

The metal has a charged ionic surface that interacted with the salts in the water. Once the surface of the metal touched the salty water the positive and negative charged particles reacted with one another, causing the spark. The metal, therefore, must have contained a charged center to hold the ions on its surface. Without any charged particles present in the pure water, it is evident that no reaction would have occurred.

Student 3

I agree with Student 2, but with one exception. The metal did not contain a charged center. The ionic surface is held together through ionic bonds between the charged particles. This forms an outer layer on the surface of the metal, which reacted with the salt particles in the water.

Had the metal contained a charged center, it would have reacted with its own outer layer and grounded any positive or negative charges on its surface.

1. The salt solute the teacher added to one of the beakers could have been which of the compounds?

A. \(H_2\)

B. CO2

C. NaCI

D. \(O_2\)

2. Which of the student(s) would agree that the metal was charged before being in the beakers?

A. Student 1 only

B. Students 2 only

C. Students 1 and 2

D. Students 2 and 3

3. Student l‘s explanation relates best to which experiment?

A. A kite flying during a thunderstorm

B. A ball thrown up in the air

C. A block sliding across sandpaper

D. An acid solution neutralized with a base solution

4. Do Students 2 and 3 differ in their explanation to why a spark occurred?

A. No. Both students claim the charged output surface of the metal caused a spark

B. No. Both students claim the charged center of the metal caused a spark

C. Yes. Student 2 argues the charged surface, caused a spark, whereas Student 3 argues the charged center caused the spark

D. Yes. Student 2 argues the charged center caused a spark, whereas Student 3 argue the charged surface caused the spark

5. Suppose the experiment is repeated with another metal having a smooth uncharged surface, but a charged center. Which of the students, if any would claim that this metal would cause a spoil with the salty water?

A. Student 1

B. Student 2

C. Student 3

D. None of the students

6. Lightning is produced when negative and positive charged particles in the clouds come in close proximity to one another, creating a spark. Which viewpoint(s) best help to describe the natural phenomenon known as lightning?

A. Student 1 only

B. Student 3 only

C. Students 2 and 3

D. All of the students

7. Suppose the teacher conducted the same experiment, but used an acetone solvent instead of water in the beakers. Based on the teacher’s demonstration and the 3 viewpoints, how would this affect the results of the experiment?

A. No reaction would occur in the salty solution.

B. A spark would occur in the pure acetone solution.

C. The salt would dissolve readily in the acetone.

D. Cannot be determined from the given information.

EXAMPLE 2:

Four early 1900s scientists discuss atomic structure, specifically the architecture of the atom. They attempt to explain the locations of electrons, protons, and neutrons within an atom.

Scientist 1

Atoms consist of positively charged centers called nuclei. Since the nuclei are positively charged, they must contain protons. The nucleus of the atom is the most dense, holding the most mass in a tiny space, whereas the area outside the nucleus is not very dense. Because foreign particles do not experience deflection when within close proximity of an atom, electrons must be located outside of the nucleus. The location of the neutron is impossible to pinpoint because of its neutral charge.

Scientist 2

I agree with Scientist 1, but with one exception. The neutron must be located within the nucleus. The mass-to-volume ratio of the nucleus is too large for the nucleus to only contain protons. There must be an additional subatomic particle located within the center and, due to the positive nature of the nucleus, that particle cannot be the electron.

Scientist 3

Atoms consist of positively charged centers called nucleoid regions. The region is not very dense, but does house most of the positively charged subatomic particles. Some protons exist outside of this region, however. Because foreign particles experience high amounts of deflection when within close proximity of an atom, neutrons and electrons must be located outside of the nucleus. The electron is too small to cause the high frequency of deflections alone.

Scientist 4

I agree with Scientist 3, but with one exception. An identical amount of protons exist outside of the nucleoid region, as well as inside. The mass-to-volume ratio of the nucleus is too small to house the majority of protons. Taking into account the high frequency of deflections outside of the nucleoid region, it is more probable for an increased number of protons to be located outside of this region.

8. Which of the scientists, if any, claimed that the atom has a positively charged center?

A. Scientists 1 and 2

B. Scientists 3 and 4

C. All of the scientists

D. None of the scientists

9. The positively charged center of which scientist’s model is most massive?

A. Scientist 1

B. Scientist 2

C. Scientist 3

D. Scientist 4

10. According to Scientist 1, as one moves farther from the center of the nucleus, the density of the atom:

A. F. increases

B. G. decreases

C. H. remains constant

D. J. varies, but with no general trend

11. It was eventually proven that all protons within an atom are located inside the nucleus. This discovery is most inconsistent with which scientist?

A. Scientist 1

B. Scientist 2

C. Scientist 3

D. Scientist 4

12. Suppose a neutral metallic ball is brought into contact with a positively charged rod. Because charges of like sign repel one another, more positive particles aggregate to the center of the ball than the outer layer. Would Scientist 3 agree or disagree with the distribution of positive particles within the ball, assuming the ball mimics the same mechanism as an atom?
    
    Would Scientist 3 agree or disagree with the distribution of positive particles within the ball, assuming the ball mimics the same mechanism as an atom?

A. Agree, because the center region of the atom has more positive particles than the outer region

B. Agree, because the center region of the atom has fewer positive particles than the outer region

C. Disagree, because the center region of the atom has more positive particles than the outer region

D. Disagree, because the center region of the atom has fewer positive particles than the outer region

13. Scientist 1, when attempting to pinpoint the location of the neutron, was most likely using which device?

A. A balance, which measures mass.

B. An electrometer, which measures electrical charge

C. A barometer, which measures pressure.

D. A lux meter, which measures the intensity of light.

14. Science textbooks show the evolution of atomic structure from its inception to present day. Which scientist best models the present day atomic structure?

A. Scientist 1

B. Scientist 2

C. Scientist 3

D. Scientist 4

EXAMPLE 3:

Blood coagulation, or clotting, is the transformation of blood from a liquid into a solid gel. Formation of a clot strengthens the seal over a break in a blood vessel. As blood in the proximity of the vessel solidifies, it can no longer flow.

The clotting cascade helps visualize the proems. When a cut occurs, platelets attach to collagen fibers and become sticky. This seal is reinforced by fibrin, which is a derivative of fibritiogrn. Fibrin is formed when prothrombin is activated, forming thrombin. Thrombin catalyzes the conversion of fibrinogen into fibrin. The threads of fibrin form the final step of the blood clot.

Hemophilia, a genetic mutation, causes excessive bleeding from even minor cuts and bruises. Four hypotheses discuss how hemophilia could interfere with the blood clotting process.

Hypothesis I

Hemophilia changes the genetic code of prothrombin produced by the body. The outer protein coat is altered, which disables the enzyme that converts prothrombin into thrombin from properly identifying the molecule. Because thrombin is never produced fibrinogen is never converted into fibrin. Thus, the final step of the clot never occurs.

Hypothesis 2

Hemophilia changes the genetic code of fibrin produced by the body. The outer protein coat is altered to such a point that the body believes it to be foreign. White blood cells then attack fibrin when produced, never allowing the final step of blood clotting to occur.

Hypothesis 3

Hemophilia changes the genetic code of fibrin produced by the body. The mechanism for Fibrin to merge together and form the blood clot is disabled. Even though the other molecules of the blood clotting process are unaltered, the disabling of fibrin prevents the final step of blood clotting from occurring.

Hypothesis 4

Hemophilia changes the genetic code of prothrombin produced by the body. When active, prothrombin produces excess fibrinogen instead of thrombin. Because thrombin is never produced fibrinogen is never converted into fibrin. Thus, the final step of the blood clot never occurs.

15. Both Hypothesis 2 and 3 indicate that the code of which molecule is altered by the genetic disorder hemophilia?

A. Prothrombin

B. Thrombin

C. Fibrinogen

D. Fibrin

16. According to the information provided, is prothrombin directly involved in the formation of a blood clot?

A. Yes, because the threads of prothrombin form the final step of the blood clot

B. Yes, because the threads of fibrin form the final step of the clot

C. No, because the threads of prothrombin form the final step of the blood clot

D. No, because the threads of fibrin form the final step of the blood clot

17. In which of the following ways do Hypotheses 1 and 2 differ with regard to how hemophilia affects the blood clotting process? Hypothesis 1 asserts that hemophilia changes the genetic code of:

A. Prothrombin, which prevents conversion into thrombin; Hypothesis 2 asserts that fibrin is altered

B. Prothrombin, which prevents conversion into fibrin; Hypothesis 2 asserts that fibrin is altered

C. Fibrin, which prevents conversion into thrombin; Hypothesis 2 asserts that prothrombin is altered

D. Thrombin; prevents conversion into Prothrombin; Hypothesis 2 asserts that prothrombin is altered

18. A substance, which behaves identically to thrombin, is injected into a patient with hemophilia. Hypothesis 3 or Hypothesis 4 argue that this patient would experience normal blood clotting?

A. Hypothesis 3, which argues hemophilia stops the production of healthy thrombin

B. Hypothesis 3, which argues hemophilia stops the production of healthy fibrin

C. Hypothesis 4, which argues hemophilia stops the production of healthy thrombin

D. Hypothesis 4, which argues hemophilia stops the production of healthy fibrin

19. Suppose it were discovered that a secondary effect of hemophilia is an abnormally low concentration of thrombin in the blood. This discovery would best agree with which hypotheses?

A. Hypotheses 1 and 3

B. Hypotheses 1 and 4

C. Hypotheses 2 and 3

D. Hypotheses 1, 3, and 4

20. Suppose healthy fibrin molecules were injected into a patient with hemophilia. Which hypotheses, if any, would support the claim that this patient would experience normal blood clotting?

A. Hypotheses 1 and 4

B. Hypotheses 2 and 3

C. All four hypotheses

D. None of the hypotheses

Solutions

1. NaC1, or sodium chloride, is a common salt in chemistry.
2. D - The first sentences of each student show us that Students 2 mentioned a charged center and Student 3 agrees with Student 2’s viewpoint
3. C - Student 1 mentions a rough surface producing friction. This matches the sandpaper mentioned in answer choice C.
4. A - Although Student 3 deviates from Student 2, they both agree with the notion that the surface of the metal caused the spark.
5. D - The smooth surface eliminates Student 1. The uncharged surface eliminates Students 2 and 3.
6. C - The key phrase in the question is “negative and positive charged particles.” Students 2 and 3 argue the charged surface of the metal causes the spark.
7. D - It is Impossible based on the information given how introducing a different solvent would change the experiment.
8. C - The first sentences of Scientists 1 and 3 state a positively charged center. Scientists 2 and 4 agree with these statements.
9. B - The key phrase in the question is “most massive.” Scientist 1 states a larger mass than Scientist 3, eliminating Scientists 3 and 4. The exception stated by Scientist 2 argues a more massive nucleus.
10. B - The key term in the question is “density.” Scientist 1 states that the nucleus is most dense, “whereas the area outside...is not very dense.’
11. D - The key phrase in the question is “all protons.. .are located inside the nucleus.” Scientists 3 and 4 mention protons outside of the nucleus. However, Scientist 4 mentions there are an equal amount of protons outside of the nucleoid region, whereas Scientist 3 states that most protons are located inside.
12. A - The key phrase in the question is “positive particles aggregate to the center.” All Scientists would agree with this statement. Answer choices G and 3 have incorrect explanations.
13. B - The last sentence of Scientist 1 states the neutron has a neutral charge. The only device that relates to “charge” is an electrometer.
14. B - It is known that all protons and neutrons are located within the nucleus, which is said by Scientist 2.
15. D - First sentences show the genetic code of fibrin is altered in Hypotheses 2 and 3, while the genetic code of prothrombin is altered in Hypothesis 1 and 4.
16. D - Answer choices A and C have incorrect explanations. Correct Answer is D.
17. A - First sentences show Hypothesis 1 states prothrombin is altered. According to the text, when prothrombin is activated it causes thrombin to form.
18. C - The key phrase of the question is “a substance.., identical to thrombin.” Hypothesis 4 states that “because thrombin is never produced fibrinogen is never converted into fibrin.”
19. B - Hypotheses 1 and 4 both state that “thrombin is never produced.” This implies a low concentration of thrombin.
20. B - First sentences of Hypotheses 2 and 3 state the genetic code of fibrin is altered by hemophilia.