The French biologist Jean-Baptiste de Lamarck (1744-1829) outlined a

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Hope you had a look at mine solution.

Sajjad1994 I got ques 6 incorrect - can you pls share explanation for the same?

­Can someone please explain the answer to Q4?

The best way to handle reading comprehension problems is to understand the purposes of each paragraph. Below is my summary of main ideas for each paragraph.

P1: Edward J. Steele is attempting to revive Lamarckism: he and his colleagues claim to have found evidence for a Lamarckian hereditary mechanism in the immune system.

P2: Some immune system cells contain genes that mutate with unusual frequency.

P3: Steele and his collegues believe a virus could carry the altered DNA to the reproductive cells and replace the DNA in those cells.

P4: Potential evidence of the mutation suggested by Steele, and skepticism from other bilogists for a circumstantial obersavation.


1. Which one of the following most accurately states the main point of the passage?

(A) The long-drided Lamarckian theory that organisms can pass on acquired characteristics to their offspring has been proven correct by the discoveries of Steele and his colleagues regarding the immune system.
(B) Steele and his colleagues have devised an account of a mechanism by which acquired characteristics could be passed on to an organism's offspring, and they claim to have found evidence for the operation of this Larnarckian mechanism.
(C) Although Steele and his colleagues have succeeded in showing that changes that occur in the immune system can be passed on to offspring, it is unlikely that a similar mechanism operates elsewhere in the body.
(D) In contrast to the standard theory of evolution, the claims of Steele and his colleagues that organisms can pass on acquired characteristics to their offspring are highly speculative and rest on purely circumstantial evidence.
(E) By showing that RNA can revert back into DNA, Steele and his colleagues have removed the main obstacle to general acceptance of the Lainarckian hypothesis that organisms can pass on acquired characteristics to their offspring.

A. "been proven". Steele and his colleagues gave a possible account of Lamarckism, but it has not been proven. Out.
B. Correct. Read the above sumamry of ideas, and you will understand why B is correct.
C. As I said, Lamarckism has not been proven. Out.
D. Indeed, the author would agree the claims of Steele and his colleagues are speculative. But this is still not the main focus of the passage. The focus is on the truthfulness of Lamarckism. Also, the passage does not contast their claims to the standard theory of evolution. Additionally, the author says circumstantial evidence can be helpful in evaluating the truthfulness of the claims of Steele and his colleagues, but the author does not mention Steele and his colleagues purely relied on circumstantial evidence. Out.
E. Again, Lamarckism has not been proven. Out.


2. The author most likely calls a certain kind of mutation a "typo" (line 25) primarily in order to

(A) distinguish it from mutations that are adaptive
(B) characterize it as relatively inconsequential
(C) indicate that it is an instance of imperfect copying
(D) emphasize that it is easily overlooked
(E) suggest an analogy between scientific investigation and textual analysis

A, B, and D are aboviously wrong.

E is illogical. Read my summary of P2: Some immune system cells contain genes that mutate with unusual frequency. P2 Talks bout mutation, a hypothetical phenomenon, but E would suggest that "typo" is used to link textual analysis to scientific investigation. But what has "textual analysis" to do with the scientific investigation or mutation? So E is out.

6. The passage most strongly suggests that the author would agree with which one of the following statements?

(A) Contrary to the opinion of most modern biologists, certain acquired characteristics probably can be passed on from one generation to the next.
(B) Steele and his colleagues have not actually observed the process of reverse transcription in immune cells.
(C) The patterns of mutations concentrated in particular areas of genes that carry instructions for immune system responses indicate that the DNA in these genes has been altered by a virus.
(D) The passing on of acquired characteristics from one generation to the next, if it occurs at all, is probably confined to the immune system.
(E) Unless a hypothesis can be confirmed by direct observation, it should be regarded as speculation rather than as science.

A. Lamarckism has not been proven. The author is still uncertain. Out.
B. Correct. They only hypothesized it, not actually observe it. Besides, the author mentions "Evolutionary mechanisms are never observed directly, so we must make do with circumstantial evidence"
C. Lamarckism has not been proven. Out.
D. The passage mentions that the passing on of acquired characteristics from one generation to the next may have to do with the immune system. But this does not mean it is confined to the immue system.
E. never mentioned.­