Cystic fibrosis is a disease that is passed down through families. It is caused by a defective gene that makes the body produce abnormally thick and sticky fluid, called mucus. This mucus builds up in the breathing passages of the lungs and in the pancreas. The buildup of mucus results in life-threatening lung infections and serious digestion problems. The disease may also affect the sweat glands and a man's reproductive system. Millions of Americans carry a CF gene, but do not have symptoms. This is because a person with CF must inherit two defective genes, one from each parent. About 1 in 29 Caucasian Americans have the CF gene. It is more common among those of northern or central European descent. Most children with CF are diagnosed by age 2. For a small number, the disease is not detected until age 18 or older. These children often have a milder form of the disease.
In context, the word 'defective' in the first sentence of the passage means which of the following?
- A. Unusual
- B. Remarkable
- C. Postponed
- D. Faulty
Correct Answer: D
Rationale: In the context provided, 'defective' means faulty, referring to the gene that causes cystic fibrosis (CF). The passage explains that CF is caused by a defective gene, resulting in the production of abnormally thick and sticky fluid. The word 'defective' suggests that the gene is not functioning correctly, leading to the symptoms associated with the disease. Therefore, 'faulty' is the correct choice. The other options, 'unusual,' 'remarkable,' and 'postponed,' do not accurately capture the meaning of 'defective' in this context and are therefore incorrect.
You may also like to solve these questions
A nanometer is a billionth of a meter. A DNA molecule is 2 nanometers in diameter. Protein molecules are about 10 nanometers in diameter. A human hair is 100,000 nanometers in diameter. But what is a nanometer and how does it relate to technology?
Nanotechnology is defined as the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, a scale at which unique properties of materials emerge that can be used to develop novel technologies and products. At the nanoscale, the physical, chemical, and biological properties of materials differ from the properties of matter either at smaller scales, such as atoms, or at larger scales that we use in everyday life such as millimeters or inches.
Nanotechnology involves imaging, measuring, modeling, and manipulating matter only a few nanometers in size. Gold nanoparticles are made of the same material as in jewelry. But when light interacts with particles of gold, different colors are reflected. The different colors can be used in simple medical tests to indicate infection or disease. Metals such as copper become extremely rigid at the nanoscale, rather than bendable as in copper wires seen in everyday use.
Which claim from the passage best describes the benefits of nanotechnology?
- A. Scientists can develop novel technologies and products.
- B. Nanotechnology is defined as the understanding and control of matter at dimensions of roughly 1 to 100 nanometers.
- C. The different colors can be used in simple medical tests to indicate infection or disease.
- D. Unique properties of materials emerge.
Correct Answer: D
Rationale: The correct answer is D because the passage specifically states that at the nanoscale, unique properties of materials emerge, which is a key benefit of nanotechnology. Choice A talks about what scientists can do but does not directly describe the benefits mentioned in the passage. Choice B is the definition of nanotechnology and not a specific benefit. Choice C mentions the use of different colors in medical tests, which is a specific application rather than a general benefit of nanotechnology.
Today, bicycles are so common that it's hard to believe they haven't always been around. But two hundred years ago, bicycles didn't even exist, and the first bicycle, invented in Germany in 1818, was nothing like our bicycles today. It was made of wood and didn't even have pedals. Since then, however, numerous innovations and improvements in design have made the bicycle one of the most popular means of recreation and transportation around the world.
In 1839, Kirkpatrick Macmillan, a Scottish blacksmith, dramatically improved upon the original bicycle design. Macmillan's machine had tires with iron rims to keep them from getting worn down. He also used foot-operated cranks like pedals, so his bicycle could be ridden at a quick pace. It didn't look much like a modern bicycle, though, because its back wheel was substantially larger than its front wheel.
In 1861, the French Michaux brothers took bicycle design a step further by introducing a metal frame, making bicycles stronger and lighter. They also used rubber tires, which provided better traction and allowed for a more comfortable ride.
Finally, in 1874, the first truly modern bicycle appeared on the scene, complete with solid rubber tires, ball bearings, and even a chain drive, which enabled the rider to pedal at a higher speed with less effort. Today bicycles are built, used, and enjoyed all over the world.
Which of the following would be the best title for this passage?
- A. Bicycles are better.
- B. A ride through the history of bicycles.
- C. Cycle your way to fitness.
- D. The popularity of bicycles.
Correct Answer: B
Rationale: The best title for this passage would be 'A ride through the history of bicycles' as it provides a comprehensive overview of the historical development of bicycles from their invention to modern times. Choice A, 'Bicycles are better,' is incorrect as it does not capture the essence of the passage, which focuses on the history and evolution of bicycles rather than their superiority. Choice C, 'Cycle your way to fitness,' is misleading as the passage does not primarily discuss the fitness aspect of cycling but instead focuses on the evolution of bicycle design. Choice D, 'The popularity of bicycles,' is too narrow as it only touches on one aspect mentioned briefly in the passage, while the passage covers a broader historical perspective.
The Moon has been worshipped by primitive peoples and has inspired humans to create everything from lunar calendars to love sonnets, but what do we really know about it? The most accepted theory about the origin of the Moon is that it was formed of the debris from a massive collision with the young Earth about 4.6 billion years ago. A huge body, perhaps the size of Mars, struck the Earth, throwing out an immense amount of debris that coalesced and cooled in orbit around the Earth.The development of Earth is inextricably linked to the Moon; the Moon's gravitational influence upon the Earth is the primary cause of ocean tides. In fact, the Moon has more than twice the effect upon the tides than does the Sun. The Moon makes one rotation and completes a revolution around the Earth every 27 days, 7 hours, and 43 minutes. This synchronous rotation is caused by an uneven distribution of mass in the Moon (essentially, it is heavier on one side than the other) and has allowed the Earth's gravity to keep one side of the Moon permanently facing Earth. It is an average distance from Earth of 384,403 km.The Moon has no atmosphere; without an atmosphere, the Moon has nothing to protect it from meteorite impacts, and thus the surface of the Moon is covered with impact craters, both large and small. The Moon also has no active tectonic or volcanic activity, so the erosive effects of atmospheric weathering, tectonic shifts, and volcanic upheavals that tend to erase and reform the Earth's surface features are not at work on the Moon. In fact, even tiny surface features such as the footprint left by an astronaut in the lunar soil are likely to last for millions of years, unless obliterated by a chance meteorite strike. The surface gravity of the Moon is about one-sixth that of the Earth's. Therefore, a man weighing 82 kilograms on Earth would only weigh 14 kilograms on the Moon.
What is the passage primarily about?
- A. What we know about the Moon and its differences from Earth
- B. A comparison of the Moon and Earth
- C. The Moon's effect on Earth
- D. The origin of the Moon
Correct Answer: A
Rationale: The correct answer is A: 'What we know about the Moon and its differences from Earth.' The passage discusses various aspects of the Moon, including its origin, gravitational influence on Earth, physical characteristics, lack of atmosphere, and surface features. It provides insights into what humans know about the Moon and highlights its differences from Earth. Choice B is incorrect because while the passage does compare certain aspects of the Moon and Earth, it primarily focuses on the Moon itself rather than a direct comparison. Choice C is incorrect as the passage briefly mentions the Moon's effect on Earth in relation to tides but does not primarily focus on this aspect. Choice D is incorrect as the origin of the Moon is mentioned in the passage, but it is not the primary focus of the text.
Cystic fibrosis is a disease that is passed down through families. It is caused by a defective gene that makes the body produce abnormally thick and sticky fluid, called mucus. This mucus builds up in the breathing passages of the lungs and in the pancreas. The buildup of mucus results in life-threatening lung infections and serious digestion problems. The disease may also affect the sweat glands and a man's reproductive system. Millions of Americans carry a CF gene, but do not have symptoms. This is because a person with CF must inherit two defective genes, one from each parent. About 1 in 29 Caucasian Americans have the CF gene. It is more common among those of northern or central European descent. Most children with CF are diagnosed by age 2. For a small number, the disease is not detected until age 18 or older. These children often have a milder form of the disease.
Which of the following describes the purpose of the passage?
- A. To describe the causes of cystic fibrosis
- B. To explain how cystic fibrosis is passed down through families
- C. To provide an overview of CF and how it is inherited
- D. To review why some Americans have CF, but others do not
Correct Answer: C
Rationale: The correct answer is C. The passage aims to provide an overview of cystic fibrosis (CF) and how it is inherited. It explains that CF is passed down through families due to a defective gene, detailing how this gene affects the body and who is most commonly affected by the disease. Choices A, B, and D are incorrect because the passage does not solely focus on describing the causes of CF, explaining how it is passed down through families, or reviewing why some Americans have CF while others do not. Instead, it provides a broader perspective on CF and its inheritance.
The Moon has been worshipped by primitive peoples and has inspired humans to create everything from lunar calendars to love sonnets, but what do we really know about it? The most accepted theory about the origin of the Moon is that it was formed of the debris from a massive collision with the young Earth about 4.6 billion years ago. A huge body, perhaps the size of Mars, struck the Earth, throwing out an immense amount of debris that coalesced and cooled in orbit around the Earth.The development of Earth is inextricably linked to the Moon; the Moon's gravitational influence upon the Earth is the primary cause of ocean tides. In fact, the Moon has more than twice the effect upon the tides than does the Sun. The Moon makes one rotation and completes a revolution around the Earth every 27 days, 7 hours, and 43 minutes. This synchronous rotation is caused by an uneven distribution of mass in the Moon (essentially, it is heavier on one side than the other) and has allowed the Earth's gravity to keep one side of the Moon permanently facing Earth. It is an average distance from Earth of 384,403 km.The Moon has no atmosphere; without an atmosphere, the Moon has nothing to protect it from meteorite impacts, and thus the surface of the Moon is covered with impact craters, both large and small. The Moon also has no active tectonic or volcanic activity, so the erosive effects of atmospheric weathering, tectonic shifts, and volcanic upheavals that tend to erase and reform the Earth's surface features are not at work on the Moon. In fact, even tiny surface features such as the footprint left by an astronaut in the lunar soil are likely to last for millions of years, unless obliterated by a chance meteorite strike. The surface gravity of the Moon is about one-sixth that of the Earth's. Therefore, a man weighing 82 kilograms on Earth would only weigh 14 kilograms on the Moon.
Why does the author mention 'impact craters' in line 16?
- A. To explain the corrosive effects of atmospheric weathering
- B. To explain why the Moon has no plant life because of meteorites
- C. To show the result of the Moon not having an atmosphere
- D. To show the result of the Moon not having active tectonic or volcanic activity
Correct Answer: C
Rationale: The mention of impact craters in the text is to highlight the consequence of the Moon lacking an atmosphere. The absence of an atmosphere on the Moon leaves it vulnerable to meteorite impacts, resulting in the multitude of impact craters on its surface. Choice A is incorrect because the mention of impact craters is not related to atmospheric weathering but rather to the lack of an atmosphere. Choice B is incorrect as it misinterprets the reason for the absence of plant life on the Moon. Choice D is incorrect as the text explicitly states that the Moon lacks tectonic or volcanic activity, which is not the focus of the mention of impact craters.
Nokea