Meteorite Impact & Dinosaur Extinction - TOEFL Reading Test

Mastering academic texts in English is crucial for success in the TOEFL Reading section. This segment mirrors the challenges of reading in English-speaking academic environments, assessing skills like identifying main ideas, extracting details, making inferences, and recognising text structure. Consistent practice is the key to excelling in this section. 

Our practice tests closely mimic the format and writing style of the actual exam, ensuring that you feel prepared and self-assured on the test day. Therefore, join us in taking the TOEFL Practice Test centered on the passage 'Meteorite Impact and Dinosaur Extinction' to familiarise yourself with the test format and note the areas for improvement!

Reading Instructions

• You have 15 minutes to read the following passage and answer all 9 questions related to it.  
• Most questions are worth 1 point, but the last question is worth more. The directions indicate how many points you will receive for that specific question. 
• The specific section/paragraphs have been provided again with the question for ease of understanding and quick solution.
• Some questions include a word or phrase that is highlighted in the question as well as in the paragraph for quick reference. 

Meteorite Impact and Dinosaur Extinction

There is increasing evidence that the impacts of meteorites have had important effects on Earth, particularly in the field of biological evolution. Such impacts continue to pose a natural hazard to life on Earth. Twice in the twentieth century, large meteorite objects are known to have collided with Earth.

If an impact is large enough, it can disturb the environment of the entire Earth and cause an ecological catastrophe. The best-documented such impact took place 65 million years ago at the end of the Cretaceous period of geological history. This break in Earth’s history is marked by a mass extinction, when as many as half the species on the planet became extinct. While there are a dozen or more mass extinctions in the geological record, the Cretaceous mass extinction has always intrigued paleontologists because it marks the end of the age of the dinosaurs. For tens of millions of years, those great creatures had flourished. Then, suddenly, they disappeared.

The body that impacted Earth at the end of the Cretaceous period was a meteorite with a mass of more than a trillion tons and a diameter of at least 10 kilometers. Scientists first identified this impact in 1980 from the worldwide layer of sediment deposited from the dust cloud that enveloped the planet after the impact. This sediment layer is enriched in the rare metal iridium and other elements that are relatively abundant in a meteorite but very rare in the crust of Earth. Even diluted by the terrestrial material excavated from the crater, this component of meteorites is easily identified. By 1990 geologists had located the impact site itself in the Yucatán region of Mexico. The crater, now deeply buried in sediment, was originally about 200 kilometers in diameter.

This impact released an enormous amount of energy, excavating a crater about twice as large as the lunar crater Tycho. The explosion lifted about 100 trillion tons of dust into the atmosphere, as can be determined by measuring the thickness of the sediment layer formed when this dust settled to the surface. Such a quantity of material would have blocked the sunlight completely from reaching the surface, plunging Earth into a period of cold and darkness that lasted at least several months. The explosion is also calculated to have produced vast quantities of nitric acid and melted rock that sprayed out over much of Earth, starting widespread fires that must have consumed most terrestrial forests and grassland. Presumably, those environmental disasters could have been responsible for the mass extinction, including the death of the dinosaurs.

Several other mass extinctions in the geological record have been tentatively identified with large impacts, but none is so dramatic as the Cretaceous event. But even without such specific documentation, it is clear that impacts of this size do occur and that their results can be catastrophic. What is a catastrophe for one group of living things, however, may create opportunities for another group. Following each mass extinction, there is a sudden evolutionary burst as new species develop to fill the ecological niches opened by the event. Impacts by meteorites represent one mechanism that could cause global catastrophes and seriously influence the evolution of life all over the planet. 

According to some estimates, the majority of all extinctions of species may be due to such impacts. Such a perspective fundamentally changes our view of biological evolution. The standard criterion for the survival of a species is its success in competing with other species and adapting to slowly changing environments. Yet an equally important criterion is the ability of a species to survive random global ecological catastrophes due to impacts. Earth is a target in a cosmic shooting gallery, subject to random violent events that were unsuspected a few decades ago. In 1991 the United States Congress asked NASA to investigate the hazard posed today by large impacts on Earth. The group conducting the 55 study concluded from a detailed analysis that impacts from meteorites can indeed be hazardous. Although there is always some risk that a large impact could occur, careful study shows that this risk is quite small.

Directions: Once you have read the passage, answer the following questions.

Paragraph 1 

There is increasing evidence that the impacts of meteorites have had important effects on Earth, particularly in the field of biological evolution. Such impacts continue to pose a natural hazard to life on Earth. Twice in the twentieth century, large meteorite objects are known to have collided with Earth.

1. 1. The word “pose” in Paragraph 1 is closest in meaning to
   1. A) Claim
   2. B) Model
   3. C) Assume
   4. D) Present

Paragraph 2

If an impact is large enough, it can disturb the environment of the entire Earth and cause an ecological catastrophe. The best-documented such impact took place 65 million years ago at the end of the Cretaceous period of geological history. This break in Earth’s history is marked by a mass extinction, when as many as half the species on the planet became extinct. While there are a dozen or more mass extinctions in the geological record, the Cretaceous mass extinction has always intrigued paleontologists because it marks the end of the age of the dinosaurs. For tens of millions of years, those great creatures had flourished. Then, suddenly, they disappeared.

1. 2. In paragraph 2, why does the author include the information that dinosaurs had flourished for tens of millions of years and then suddenly disappeared?
   1. A) To support the claim that the mass extinction at the end of the Cretaceous is the best-documented of the dozen or so mass extinctions in the geological record
   2. B) To explain why as many as half of the species on Earth at the time are believed to have become extinct at the end of the Cretaceous
   3. C) To explain why paleontologists have always been intrigued by the mass extinction at the end of the Cretaceous
   4. D) To provide evidence that an impact can be large enough to disturb the environment of the entire planet and cause an ecological disaster

Paragraph 3

The body that impacted Earth at the end of the Cretaceous period was a meteorite with a mass of more than a trillion tons and a diameter of at least 10 kilometers. Scientists first identified this impact in 1980 from the worldwide layer of sediment deposited from the dust cloud that enveloped the planet after the impact. This sediment layer is enriched in the rare metal iridium and other elements that are relatively abundant in a meteorite but very rare in the crust of Earth. Even diluted by the terrestrial material excavated from the crater, this component of meteorites is easily identified. By 1990 geologists had located the impact site itself in the Yucatán region of Mexico. The crater, now deeply buried in sediment, was originally about 200 kilometers in diameter.

1. 3. Which of the following can be inferred from paragraph 3 about the location of the meteorite impact in Mexico?
   1. A) The location of the impact site in Mexico was kept secret by geologists from 1980 to 1990
   2. B) It was a well-known fact that the impact had occurred in the Yucatán region.
   3. C) Geologists knew that there had been an impact before they knew where it had occurred.
   4. D) The Yucatán region was chosen by geologists as the most probable impact site because of its climate.

1. 4. According to paragraph 3, how did scientists determine that a large meteorite had impacted Earth?
   1. A) They discovered a large crater in the Yucatán region of Mexico.
   2. B) They found a unique layer of sediment worldwide.
   3. C) They were alerted by archaeologists who had been excavating in the Yucatán region
   4. D) They located a meteorite with a mass of over a trillion tons.

Paragraph 4

This impact released an enormous amount of energy, excavating a crater about twice as large as the lunar crater Tycho. The explosion lifted about 100 trillion tons of dust into the atmosphere, as can be determined by measuring the thickness of the sediment layer formed when this dust settled to the surface. Such a quantity of material would have blocked the sunlight completely from reaching the surface, plunging Earth into a period of cold and darkness that lasted at least several months. The explosion is also calculated to have produced vast quantities of nitric acid and melted rock that sprayed out over much of Earth, starting widespread fires that must have consumed most terrestrial forests and grassland. Presumably, those environmental disasters could have been responsible for the mass extinction, including the death of the dinosaurs.

1. 5. The word “excavating” in paragraph 4 is closest in meaning to
   1. A) digging out
   2. B) extending
   3. C) destroying
   4. D) covering up

1. 6. According to paragraph 4, all of the following statements are true of the impact at the end of the Cretaceous period EXCEPT:
   1. A) A large amount of dust blocked sunlight from Earth.
   2. B) Earth became cold and dark for several months.
   3. C) New elements were formed in Earth’s crust.
   4. D) Large quantities of nitric acid were produced.

Paragraphs 5

Several other mass extinctions in the geological record have been tentatively identified with large impacts, but none is so dramatic as the Cretaceous event. But even without such specific documentation, it is clear that impacts of this size do occur and that their results can be catastrophic. What is a catastrophe for one group of living things, however, may create opportunities for another group. Following each mass extinction, there is a sudden evolutionary burst as new species develop to fill the ecological niches opened by the event. Impacts by meteorites represent one mechanism that could cause global catastrophes and seriously influence the evolution of life all over the planet. 

1. 7. The phrase “tentatively identified” in paragraph 5 is closest in meaning to
   1. A) identified after careful study
   2. B) identified without certainty
   3. C) occasionally identified
   4. D) easily identified

Paragraph 6

According to some estimates, the majority of all extinctions of species may be due to such impacts. Such a perspective fundamentally changes our view of biological evolution. The standard criterion for the survival of a species is its success in competing with other species and adapting to slowly changing environments. Yet an equally important criterion is the ability of a species to survive random global ecological catastrophes due to impacts. Earth is a target in a cosmic shooting gallery, subject to random violent events that were unsuspected a few decades ago. In 1991 the United States Congress asked NASA to investigate the hazard posed today by large impacts on Earth. The group conducting the 55 study concluded from a detailed analysis that impacts from meteorites can indeed be hazardous. Although there is always some risk that a large impact could occur, careful study shows that this risk is quite small.

1. 8. The word “perspective” in paragraph 6 is closest in meaning to
   1. A) sense of values
   2. B) point of view
   3. C) calculation
   4. D) complication

Paragraph 7

Impacts by meteorites represent one mechanism that could cause global catastrophes and seriously influence the evolution of life all over the planet. (A) According to some estimates, the majority of all extinctions of species may be due to such impacts. (B) Such a perspective fundamentally changes our view of biological evolution. (C) The standard criterion for the survival of a species is its success in competing with other species and adapting to slowly changing environments. (D) Yet an equally important criterion is the ability of a species to survive random global ecological catastrophes due to impacts.

1. 9. Directions: Review the excerpt from the passage provided above. The letters (A), (B), (C), and (D) denote where the subsequent sentence could be incorporated.
   
   This is the criterion emphasised by Darwin’s theory of evolution by natural selection. 
   
   Where would the sentence most appropriately belong?
   1. A) Choice A
   2. B) Choice B
   3. C) Choice C
   4. D) Choice D

Hold on!  Before checking your answers and matching them, explore the TOEFL Exam Pattern and Syllabus!

Answer Key with Explanation for TOEFL Reading Passage - Meteorite Impact & Dinosaur Extinction

1.  Answer: D

Explanation:  The correct answer is option D. The word "pose" in the context of the sentence "Such impacts continue to pose a natural hazard to life on Earth" means to present or to constitute. It indicates that meteorite impacts continue to present or constitute a natural hazard to life on Earth.

2. Answer: C

Explanation: The correct answer is option C. The paragraph mentions that dinosaurs flourished for tens of millions of years and then suddenly disappeared. This information is included to explain why paleontologists have always been intrigued by the mass extinction at the end of the Cretaceous period. The sudden disappearance of dinosaurs is a notable event in Earth's history and is closely linked to the mass extinction event caused by the meteorite impact, which is the focus of paleontological interest. Therefore, option C is the most appropriate answer as it directly addresses the author's purpose in including that information.

3. Answer: C

Explanation: The correct answer is option C. The paragraph states that scientists identified the impact from the worldwide layer of sediment enriched in iridium and other meteoritic elements, which was found first. They later located the impact site in the Yucatán region of Mexico. This sequence of events implies that scientists recognised the occurrence of a meteorite impact before pinpointing the exact location where it happened.

4. Answer: B

Explanation: The correct answer is option B. According to the paragraph, scientists determined that a large meteorite had impacted Earth by identifying a worldwide layer of sediment that contained iridium and other elements typical of meteorites. This layer was deposited globally after the impact and served as evidence of a large extraterrestrial event. Therefore, option B correctly describes how scientists initially identified the impact event.

5. Answer: A

Explanation: The correct answer is option A. The word "excavating" in the context means to dig out or remove material. It describes the action of the impact in creating a crater about twice as large as the lunar crater Tycho. Therefore, "digging out" is the closest meaning to "excavating."

6. Answer: C

Explanation: The correct answer is option C. There is no mention in the paragraph about new elements being formed in Earth's crust as a result of the impact. The passage focuses on the environmental effects such as sunlight blockage and nitric acid production, but does not discuss the formation of new elements in the Earth's crust. Therefore, option C is the statement that is NOT true based on the information provided in paragraph 4.

7. Answer: B

Explanation: The correct answer is option B. The phrase "tentatively identified" suggests that other mass extinctions in the geological record have been identified with large impacts, but not definitively or with absolute certainty. Therefore, "identified without certainty" best captures the meaning of "tentatively identified."

8. Answer: B

Explanation: The correct answer is option B. In the context of paragraph 6, the word "perspective" refers to a particular point of view or way of looking at something. It signifies that considering the majority of extinctions being due to impacts fundamentally changes how we view biological evolution. Therefore, "point of view" is the closest meaning to "perspective" in this context. This choice reflects how understanding the role of impacts in extinctions shifts our understanding of evolutionary processes, highlighting the importance of catastrophic events alongside traditional factors like competition and adaptation.

9. Answer: D

Explanation: The correct answer is option D. This is an Insert Text question where you are required to select the appropriate place to insert the provided sentence within the passage. The sentence in question would reinforce the idea presented in statement (D) that surviving random global ecological catastrophes is an equally important criterion for species survival. This aligns with Darwin's theory of natural selection, where species' ability to survive and adapt to their environment, including sudden catastrophic events, plays a crucial role in their evolutionary success. Therefore, choice D is the correct answer as it logically follows statement (D) to complete the paragraph's thought.

Well done on completing the "Meteorite Impact and Dinosaur Extinction" practice test! Curious to dive deeper into TOEFL preparation? We offer an array of resources designed to enhance your skills and familiarity with the exam format. Whether it's practice tests, study guides, or tips, we're here to support your learning journey.

So, why wait? Click on the next practice test and start your journey to success!

Also Read:

• How to Prepare for TOEFL: A Definitive Guide to Effective Preparation
• Craftsmen vs Industrialization - TOEFL Reading Practice Questions with Answer Key