About a century ago, the Swedish physical scientist Arrhenius proposed

1. The author of the passage is primarily concerned with
(C) explaining how current research in chemistry may be related to broader biological concerns
The author states the research in chemistry in para 1 and in further detail in the second para
The author further states the broader biological concerns towards the end of the second para by stating :
Their conclusions, although strongly disputed, have generated excitement among investigators such as myself who are proposing that the galactic clouds are the places where the prebiological evolution of compounds necessary to life occurred.

2. According to the passage, classical chemical reactions and tunneling reactions are alike in which of the following ways?
(B) In both types of reactions, a transition is made from the bottom of one potential well to the bottom of another.
The author states the following in the 2nd para:
1) A chemical reaction corresponds to the transition of a molecule from the bottom of one potential well to the bottom of another.
2) In classical chemistry, such a transition can be accomplished only by going over the potential barrier between the wells, the height of which remains constant and is called the activation energy of the reaction.
3) In tunneling, the reacting molecules tunnel from the bottom of one to the bottom of another well without having to rise over the barrier between the two wells.
Thus, from the above, in chemical reactions v/s tunneling reactions, we can understand that in both types of reactions, a transition is made from the bottom of one potential well to the bottom of another

3. According to the Arrhenius equation as discussed in the passage, which of the following statements about chemical reactions is true?
(A) Chemical reactions are less likely to occur at temperatures close to absolute zero
The author states in para 1 :
According to the Arrhenius equation, chemical reactions are increasingly unlikely to occur as temperatures approach absolute zero, and at absolute zero (zero degrees Kelvin, or minus 273 degrees Celsius) reactions stop.

4. The author’s attitude toward the theory of a cold pre-history of life can best be described as
(A) neutral =. the author shows a positive attitude towards the topic in the last para, hence, incorrect
(B) skeptical => this is the opposite, hence, incorrect
(C) mildly positive => correct
(D) very supportive => 'very' is too extreme here and moreover, the author is not supportive of anything, hence incorrect
(E) pointedly critical => this is the opposite, hence, incorrect

5. The author’s hypothesis concerning the cold prehistory of life would be most weakened if which of the following were true?
(A) Cosmic rays are unlikely to trigger the formation of simple molecules.
The author's hypothesis begins from (i.e it is the first step of his hypothesis):
Cosmic rays (high-energy protons and other particles) might trigger the synthesis of simple molecules, such as interstellar formaldehyde, in dark clouds of interstellar dust.
Therefore, if the cosmic rays are unlikely to trigger the formation of simple molecules, then the authors hypothesis is weakened, as the further steps regarding the formation of complex organic molecules, slowly but surely, by means of tunneling => would not be valid. Hence (A) is correct

6. Which of the following best describes the hypothesis of Hoyle and Wickramasinghe as it is presented in the passage?
I used the POE method to answer this question:
(A) Cosmic rays can directly synthesize complex organic molecules=> the same is mentioned in the author's hypothesis and moreover it is given in the passage that cosmic rays might trigger the synthesis of simple molecules and not complex. hence incorrect
(B) The galactic clouds are the places where prebiological evolution of compounds necessary to life occurred. => the author mentions that the conclusions of Hoyle and Wickramasinghe are strongly disputed and further mentions that it is the investigators like him, who propose that the galactic clouds are the places where prebiological evolution of compounds necessary to life occurred. hence, incorrect.
(C) Interstellar formaldehyde can be synthesized by tunneling. => The passage mentions that interstellar formaldehyde are simple molecules, whose synthesis might be triggered by cosmic waves, and not by tunneling. Hence, incorrect
(D) Molecules of interstellar formaldehyde can evolve into complex organic molecules. => Correct
(E) Complex organic molecules can be synthesized from stable polysaccharides such as cellulose and starch. => the hypothesis of Hoyle and Wickramasinghe mentions that
molecules of interstellar formaldehyde have indeed evolved into stable polysaccharides such as cellulose and starch. The passage does not mention whether complex organic molecules can be synthesized from stable polysaccharides such as cellulose and starch. Hence, incorrect.


7. Which of the following best describes the organization of the first two paragraphs of the passage?
(D) The author presents a law of classical chemistry in order to introduce a kind of chemical reaction that differs from it and then explains the essential difference between the two.
1) The author mentions a law of classical chemistry in the first para.
2) He then introduces a different kind of chemical reaction (quantum-mechanical effect known as tunneling : this effect accounts for chemical reactions that are forbidden by the principles of classical chemistry)
3) The author mentions the essential difference between the 2 in the first half of the second para.