Aristotelian abiogenesis, also known as spontaneous generation,
was the theory according to which fully formed living organisms sometimes
arise from not-living matter. Aristotle explicitly taught this form of abiogenesis,
and laid it down as an observed fact that some animals spring from putrid
matter, that plant lice arise from the dew which falls on plants, that fleas
are developed from putrid matter, that mice come from dirty hay, and so
forth.
The first step in the scientific refutation of the theory of Aristotelian
abiogenesis was taken by the Italian Francesco Redi, who, in 1668, proved
that no maggots were bred in meat on which flies were prevented by wire
screens from laying their eggs. From the seventeenth century onwards it
was gradually shown that, at least in the case of all the higher and readily
visible organisms, spontaneous generation did not occur, but that omne vivum
ex ovo, every living thing came from a pre-existing living thing.
The invention of the microscope carried the refutation further. In 1683
Antoni van Leeuwenhoek discovered bacteria, and it was soon found that however
carefully organic matter might be protected by screens, or by being placed
in stoppered receptacles, putrefaction set in, and was invariably accompanied
by the appearance of myriads of bacteria and other low organisms. Then, in
1768, Lazzaro Spallanzani proved that microbes came from the air, and could
be killed by boiling. His work paved the way for Louis Pasteur.
It was due chiefly to Louis Pasteur that the occurrence of abiogenesis in
the microscopic world was disproved as much as its occurrence in the macroscopic
world. If organic matter were first sterilized and then prevented from contamination
from without, putrefaction did not occur, and the matter remained free from
microbes. The presence of bacteria, or their spores, is so universal that
only extreme precautions guard against a re-infection of the sterilized
material. It was thus concluded definitely that all known living organisms
arise only from pre-existing living organisms.
1. The passage suggests that Aristotle:
I. believed organisms emerge from non-living matter
II. was unaware of the microscopic world
III. was the only theorist to teach spontaneous generation
(A) I only
(B) II only
(C) I and II only
(D) I and III only
(E) I, II and III
2. The author's main purpose is to:
(A) chronicle a set of scientific discoveries
(B) describe the history of bacteria science
(C) follow a theory from its creation to refutation
(D) theorize about the nature of the generation of life
(E) illuminate the meaning of a term in science
3. Redi's discovery is important because:
I. The discovery paved the way for Louis Pasteur's discovery
II. Redi proved that maggots arise from eggs, not from meat.
III. The discovery showed that life comes from other life.
(A) I only
(B) III only
(C) I and III only
(D) II and III only
(E) I, II and III
4. The tone of the passage is:
(A) factual
(B) concerned
(C) inquisitive
(D) bombastic
(E) critical
5. This passage is most likely to be found in a(n):
(A) newspaper editorial
(B) biography of Artistole
(C) history textbook
(D) scientific journal
(E) encyclopedia
1. The passage suggests that Aristotle:
I. believed organisms emerge from non-living matter
II. was unaware of the microscopic world
III. was the only theorist to teach spontaneous generation
(A) I only
(B) II only
(C) I and II only
(D) I and III only
(E) I, II and III
Type: Inference
(C) The first paragraph clearly states that Aristotle wrote about Abiogenesis: "the theory according to which fully formed living organisms sometimes
arise from not-living matter." Thus, I is correct. The third paragraph
explains that once the microscopic world was discovered it became clear that bacteria
was everywhere and as soon as an organism began to decay, bacterial life was everywhere.
Had Aristotle known this, he probably would have changed his theory. The microscopic
world was discovered many centuries after Aristotle, so he was definitely unaware
of it, making II correct. Although Aristotle may have originated the idea of Abiogenesis,
he is unlikely to be the only theorist to teach the theory. Furthermore, the passage
never states that Aristotle was the only teacher, so III cannot be correct. (500)
2. The author's main purpose is to:
(A) chronicle a set of scientific discoveries
(B) describe the history of bacteria science
(C) follow a theory from its creation to refutation
(D) theorize about the nature of the generation of life
(E) illuminate the meaning of a term in science
Type: Purpose of the passage
(C) The first paragraph describes Aristotelian Abiogenesis: the theory of spontaneous
generation. The second, third and fourth paragraphs explain how over time the
theory was slowly refuted due to new discoveries in science. Thus (C) is correct.
(A) is partly true, but the author's purpose is to focus on the theory of Abiogenesis
and how it was proved wrong, not just to write a history of discoveries that were
made. (B) is incorrect because bacteria is mentioned only in the third and fourth
paragraphs, and comes up as part of the proof for the Abiogenesis theory being
wrong, not as a general history of bacteria science. (D) confuses some of the
ideas in the passage with the actual purpose of the passage. While all the scientists
in the passage theorized about the generation of life, the purpose of the passage
itself is not to theorize. The passage does (E) "illuminate the meaning of
a term in science" but that is only a small part of the passage and not the
main purpose of it. (600)
3. Redi's discovery is important because:
I. The discovery paved the way for Louis Pasteur's discovery
II. Redi proved that maggots arise from eggs, not from meat.
III. The discovery showed that life comes from other life.
(A) I only
(B) III only
(C) I and III only
(D) II and III only
(E) I, II and III
Type: Detail of the passage
(D) I is incorrect because Spallanzani's experiment, not Redi's, paved the way
for Pasteur's. II is correct, because the passage states "Redi...proved
that no maggots were bred in meat on which flies were prevented by wire screens
from laying their eggs." III is correct, because the next sentence states
that "From the seventeenth century onwards it was gradually shown that...every
living thing came from a pre-existing living thing." Thus, Redi was
the first to show that life (maggots) came from other life (eggs). (500)
4. The tone of the passage is:
(A) factual
(B) concerned
(C) inquisitive
(D) bombastic
(E) critical
Type: Tone
(A) The author simply describes a theory and how it was refuted and
is completely factual in his or her retelling of history. Since the author is
detached from personal opinion, he or she cannot be (E) critical. The passage
contains no displays of emotion. Thus, (B) and (D) are also incorrect. The author
also does not ask any questions in the passage. The question that comes up in
the passage is that of whether Abiogenesis occurs. However, the question is examined
and ultimately answered; it is not posed by the author. (600)
5. This passage is most likely to be found in a(n):
(A) newspaper editorial
(B) biography of Artistole
(C) history textbook
(D) scientific journal
(E) encyclopedia
Type: Category of Writing
(E) This passage discusses one scientific theory and its refutation. It is likely
to be found in an encyclopedia under the term "Abiogenesis." The passage's
focus on a single theory makes it unlikely to appear in a history textbook (C),
as a history textbook is too general to go into detail on one specific theory.
The theory is also an ancient theory which was completely proven wrong by the
time of Louis Pasteur, over a century ago. Because the passage discusses the past
it cannot be from a (D) scientific journal. The passage also only specifically
discusses Aristotle in the first paragraph, so it is unlikely to come from his
biography (B). Because, as we said in question 4, the passage contains no opinion
or emotion, it cannot be from an editorial. (700)
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