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gondwana

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Gondwana
Paragragh 1: Among the (enduring) legacies of the famous European voyages of
discovery in the eighteenth and nineteenth centuries are a collection and scientific
description of plants and animals from around the world. These form the nucleus of the
great collections in modern museums and have been responsible for a radical revision
in the way that we perceive the structure of Earth and the forces that have shaped its
surface over time. As the fauna and flora from far-flung lands came to be described and
incorporated into the body of knowledge about the world, it was noted that there were
some striking similarities among living and extinct organisms of the Southern
Hemisphere continents.【In the 1840s, the English botanist Sir Joseph Dalton Hooker
commented on the remarkable fact that the flora of South America and Oceania (mainly
Australia, New Zealand, New Guinea, and the Malay Archipelago) shared seven
families of flowering plants and 48 genera that were not to be found elsewhere. 】
Later, similar patterns were observed in other groups of plants and animals, such as
liverworts, lichens, mayflies, midges, and various types of vertebrates. How could these
similarities be explained in view of the enormous stretches of ocean that separate the
Southern Hemisphere continents today One idea developed during the late nineteenth
century was that there existed in the remote geological past a vast Southern Hemisphere
continent in other words, that the modern continents of the Southern Hemisphere were
somehow connected long ago, thus explaining the similarities in fauna and flora.The
name given to this hypothetical continent was Gondwana.
1..The word enduring in the passage is closest in meaning to
○ exciting
○ lasting
○ unexpected
○ well-known
2..Why does the author mention the enormous stretches of ocean that separate the
Southern Hemisphere continents today
○ To emphasize the importance of the famous European voyages of discovery in the
eighteenth and nineteenth centuries
○ To suggest a reason why so many genera of flowering plants are found only in the
Southern Hemisphere
○ To question the accuracy of Sir Joseph Dalton Hooker's observations about the
similarities between the flora of Australia and that of South America
○ To explain why the similarities between flora pointed out by Sir Joseph Dalton
Hooker seemed so remarkable
3.Which of the sentences below best expresses the essential information in the
highlighted sentence in the passage Incorrect choices change the meaning in
important ways or leave out essential information.
○ The similarities in fauna and flora across Southern Hemisphere continents were
explained in the late nineteenth century.
○ In the nineteenth century it was discovered that the Southern Hemisphere continents
contain fauna and flora that are highly similar.
○ In the nineteenth century, it was suggested that the modern continents of the Southern
Hemisphere were once connected.
○ The fauna and flora of the modern continents of the Southern Hemisphere were found
to be very similar in the late nineteenth century.
Paragragh 2: One of the most distinctive fossil plants of this hypothetical continent is
called Glossopteris. ■When first described by the French paleobotanist Adolphe
Brongniart in 1828, Glossopteris was thought to be a type of fern. ■Now, however, it is
known to be a woody seed-bearing shrub or tree. ■The trunks of Glossopteris could
reach 4 meters in height.■ Seeds and pollen-containing organs were borne in clusters
at the tips of slender stalks attached to the leaves, but some species may have borne
seeds in cones. It is thought that Glossopteris lived in a seasonal environment, and this
is consistent with the occurrence of growth rings in the wood. Also, there is evidence
that the plant was deciduous (that is, that it shed its leaves annually at the end of the
growing season) and that it grew under very wet soil conditions, like the modern swamp
cypress. The large leaves of Glossopteris which exceeded 30 centimeters in length are
common fossils in rocks of the Permian period (299¨C251 million years ago) in India,
Africa, South America, Australia, and Antarctica.
4..In paragraph 2, the author discusses Glossopteris in order to
○ provide an example of a fossil species that was attributed to Gondwana on the basis
of its wide distribution
○ explain why the descriptions of ancient plants made by Adolphe Brongniart were not
completely accurate
○ establish the importance of nineteenth-century paleobotanist Adolphe Brongniart
○ show that similarities among flora in the Southern Hemisphere continents were not
limited to flowering plants
5..According to paragraph 2, current evidence indicates that Glossopteris had all of the
following characteristics EXCEPT:
○ It was deciduous.
○ It was a type of fern.
○ It had large leaves.
○ It grew in wet soil conditions.
6..According to paragraph 2, what suggests that Glossopteris may have lived in a
seasonal environment
○ It grew in what is now Antarctica.
○ It was a seed-bearing plant.
○ There is evidence that it lost its leaves annually.
○ There were stalks attached to its leaves.
Paragragh 3: At the time the Gondwana hypothesis was conceived, the (prevailing)
theory of Earth saw continents as fixed in their relative positions. The problem of
linking up the various elements of Gondwana was solved by hypothesizing the
existence of ancient land bridges. This changed in 1912 with the proposal of the theory
of continental drift by the German meteorologist and geophysicist Alfred Wegener, an
idea that was later developed and championed by the famous South African geologist
Alex Logan du Toit. Wegener and du Toit argued that the continents are not fixed; rather,
they have moved apart or drifted to their present-day positions. In the past, Gondwana
was a single contiguous landmass comprising the present-day Southern Hemisphere
continents.
7..The word prevailing in the passage is closest in meaning to
○ best understood
○ most controversial
○ generally accepted
○ recently proposed
8..According to paragraph 3, why did geologists initially hypothesize the existence of
ancient land bridges across continents
○ To explain how the continents may have drifted to their present-day positions
○ To explain how organisms could spread across distant continents
○ To argue against Wegener's theory of continental drift
○ To help explain the present-day positions of the Southern Hemisphere continents
9..According to paragraph 3, what did Alfred Wegener and Alex Logan du Toit have in
common
○ Both were originally trained as meteorologists.
○ Both had doubts about the hypothesis that Gondwana was once a single contiguous
landmass.
○ Both believed that continents change their position over time.
○ Both believed that the present-day Southern Hemisphere continents were too far apart
to have been linked by a land bridge.
Paragragh 4: These ideas seemed (incredible) at the time, but in support of their theory
Wegener and du Toit pointed to similarities in fauna and flora, and the distributions of
fossils such as Glossopteris provided an important piece of evidence in the assembly of
the Gondwana jigsaw puzzle. Wegener and du Toit also drew together other different
sources of evidence, such as the remarkable geometric fit of South America and Africa,
and similarities between the ages and types of rock found in areas of Southern
Hemisphere continents that are now thousands of miles apart. The notion of drifting
continents only became widely accepted in the 1960s following the discovery of
paleomagnetism (the study of changes in the polarity of Earth's magnetic field through
time) and the development of the theory of plate tectonics, which explained the growth
and movement of continents and other geological phenomena.
10..The word incredible in the passage is closest in meaning to
○ unfamiliar
○ unsupported
○ hard to understand
○ impossible to believe
11..According to paragraph 4, Wegener and du Toit offered all of the following evidence
in support of their hypothesis EXCEPT
○ distributions of fossils across the Southern Hemisphere continents
○ the geometric fit of South America and Africa
○ similarities in rocks across the Southern Hemisphere continents
○ differences in geological phenomena across the Southern Hemisphere continents
12..Paragraph 4 strongly suggests that the theory of continental drift was not widely
accepted before the 1960s in part because
○ the distributions of fossils such as Glossopteris were not yet generally known
○ other explanations for the geometric fit of South America and Africa were available
○ there was no satisfactory explanation for the movement of continents
○ few scientists accepted the claims made by Wegener and du Toit about the similarities
in the ages of groups of rocks
13..Look at the four squares that indicate where the following sentence could be added
to the passage.
This led to its name, which means tongue fern in Greek and is a reference to its tongueshaped leaves.
Where would the sentence best fit Click on a square to add the sentence to the passage.
Paragragh 2: One of the most distinctive fossil plants of this hypothetical continent is
called Glossopteris. ■When first described by the French paleobotanist Adolphe
Brongniart in 1828, Glossopteris was thought to be a type of fern. ■Now, however, it is
known to be a woody seed-bearing shrub or tree. ■The trunks of Glossopteris could
reach 4 meters in height.■ Seeds and pollen-containing organs were borne in clusters
at the tips of slender stalks attached to the leaves, but some species may have borne
seeds in cones. It is thought that Glossopteris lived in a seasonal environment, and this
is consistent with the occurrence of growth rings in the wood. Also, there is evidence
that the plant was deciduous (that is, that it shed its leaves annually at the end of the
growing season) and that it grew under very wet soil conditions, like the modern swamp
cypress. The large leaves of Glossopteris which exceeded 30 centimeters in length are
common fossils in rocks of the Permian period (299¨C251 million years ago) in India,
Africa, South America, Australia, and Antarctica.
14..Drag your choices to the spaces where they belong. To review the passage, click on
View Text.
Answer Choices
○ The plants and animals collected during the eighteenth- and nineteenth-century
voyages of discovery made it possible to advance important scientific theories.
○ By 1828, fossils of Glossopteris had been discovered to have inhabited both the
Northern and Southern Hemisphere continents in the remote geological past.
○ To explain the observed distribution patterns of flora and fauna, scientists
hypothesized that land bridges had linked the widely separated Southern Hemisphere
continents in the geological past.
○ The theory of continental drift, proposed in 1912, held that the Southern Hemisphere
continents once formed an unbroken landmass and subsequently moved apart to their
present locations.
○ To support their hypothesis that continents are not fixed in their relative positions,
Alfred Wegener and Alex Logan du Toit used paleomagnetic evidence to develop the
theory of plate tectonics.
○ Continental drift explained the distribution of organisms as well as the similarities in
rocks and the geometric fit of Africa and South America, but the theory was not
generally accepted until the 1960s.
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