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Time–15 minutes
Read the passages and choose the best answer to each question. Answer all questions about a passage on the basis of what is stated or implied in that passage.
1 Everyone on Earth is continually exposed to small, relatively harmless amounts of ionizing radiation, known as background radiation, from natural sources such as soil and rock. However, other types of ionizing radiation—x–rays, ultraviolet radiation from the sun, and alpha, beta, and gamma radiation emitted by radioactive isotopes—have the potential to harm the human body. Ionizing radiation has enough energy to remove one or more electrons from the atoms it hits to form positively charged ions that can react with and damage living tissue. Most damage occurs in tissues with rapidly dividing cells, such as the bone marrow, where blood cells are made, and the digestive tract, whose lining must be constantly renewed.
2 Exposure to ionizing radiation can damage cells in two ways. The first is genetic damage, which alters genes and chromosomes. This can show up as a genetic defect in children or in later generations. The second type of damage is somatic, which causes victims direct harm in the form of burns, miscarriages, eye cataracts, some types of leukemia, or cancers of the bone, thyroid, breast, skin, and lung. Small doses of ionizing radiation over a long period of time cause less damage than the same total dosage given all at once. Exposure to a large dose of ionizing radiation over a short time can be fatal within a few minutes to a few months later.
1. According to the passage, what is one difference between background radiation and other types of ionizing radiation?
A Background radiation is rare in nature,while other types are not.
B Background radiation is less likely to harm the human body.
C Background radiation cannot form positively charged ions.
D Background radiation causes more damage to the environment.
2. What types of tissues are harmed most by ionizing radiation?
A Tissues with cells that divide quickly
B Tissues on the outside surface of the body
C Tissues exposed to background radiation
D Tissues with a large number of chromosomes
3. All of the following are examples of somatic damage EXCEPT
A genetic defects
B eye cataracts
C radiation burns
D lung cancer
4. Which exposure to ionizing radiation causes the most serious damage to humans?
A Continuous exposure to background radiation in the environment
B Small doses of ionizing radiation over a long period of time
C A single dose of a moderate amount of ionizing radiation
D Exposure to a large amount of ionizing radiation in a short period
1 All North American canids have a doglike appearance characterized by a graceful body, long muzzle, erect ears, slender legs, and bushy tail. Most are social animals that travel and hunt in groups or pairs. After years of persecution by humans, the populations of most North American canids, especially wolves and foxes, have decreased greatly. The coyote, however, has thrived alongside humans, increasing in both numbers and range.
2 Its common name comes from coyotl, the term used by Mexico’s Nahuatl Indians,and its scientific name, canis latrans, means “barking dog.” The coyote’s vocalizations are varied, but the most distinctive are given at dusk, dawn, or during the night and consist of a series of barks followed by a prolonged howl and ending with short, sharp yaps. This call keeps the band alert to the locations of its members. One voice usually prompts others to join in, resulting in the familiar chorus heard at night throughout the West.
3 The best runner among the canids, the coyote is able to leap fourteen feet and cruise normally at 25–30 miles per hour. It is a strong swimmer and does not hesitate to enter water after prey. In feeding, the coyote is an opportunist, eating rabbits, mice, ground squirrels, birds, snakes, insects, many kinds of fruit, and carrion—whatever is available. To catch larger prey, such as deer or antelope, the coyote may team up with one or two others,running in relays to tire prey or waiting in ambush while others chase prey toward it. Often a badger serves as involuntary supplier of smaller prey: while it digs for rodents at one end of their burrow, the coyote waits for any that may emerge from an escape hole at the other end.
4 Predators of the coyote once included the grizzly and black bears, the mountain lion,and the wolf, but their declining populations make them no longer a threat. Man is the major enemy, especially since coyote pelts have become increasingly valuable, yet the coyote population continues to grow, despite efforts at trapping, shooting, and poisoning the animals.
5. According to the passage, the coyote is unlike other North American canids in what way?
A The coyote’s body is not graceful.
B The coyote is not hunted by humans.
C The coyote population has not decreased.
D The coyote does not know how to swim.
6. All of the following statements describe the coyote’s vocalizations EXCEPT:
A Vocalizations communicate the locations of other coyotes.
B The coyote uses its distinctive call to trick and catch prey.
C A group of coyotes will often bark and howl together.
D The coyote’s scientific name reflects its manner of vocalizing.
7. According to the passage, the coyote is an opportunist because it
A knows how to avoid being captured
B likes to team up with other coyotes
C has better luck than other predators
D takes advantage of circumstances
8. Which animal sometimes unknowingly helps the coyote catch food?
A Wolf
B Rodent
C Deer
D Badger
9. According to the passage, the chief predator of the coyote is
A the wolf
B the mountain lion
C the human
D the grizzly bear
10. According to the passage, all of the following statements are true EXCEPT:
A The coyote is a serious threat to human activities.
B The coyote is a skillful and athletic predator.
C The coyote hunts cooperatively with other coyotes.
D The coyote survives despite persecution by humans.
Answers to Reading Quiz 1 are on page 635.
Record your score on the Progress Chart on page 790.
PROGRESS–1.1 through1.2