Questiоns 19-30 аre bаsed оn the fоllowing pаssage Toxic Agents in the Environment 1 Determining what types and levels of risk a potential toxicant might pose requires diligent scientific work, both in the laboratory and in the field. Shortly we will look at how scientists study the effects of toxicants in the lab, but first let's quickly survey what kinds of toxic agents exist around us and how they behave and move through the environment. Toxicants come in many different types 2 Toxicants can be classified into different types based on their health effects. The best-known arecarcinogens, chemicals or types of radiation that cause cancer. In cancer, certain malignant cells growuncontrollably, creating tumors, damaging the body's functioning, and often leading to death. In our society today, the greatest number of cancer cases is thought to result from carcinogens contained in cigarette smoke. Carcinogens can be difficult to identify because there may be a long lag time between exposure to the agent and the detectable onset of cancer. Historically, much toxicological work focused on carcinogens. Now, however, we know that toxicants can produce many different types of effects, so scientists have many more endpoints, or health impacts, to look for. 3 Mutagens are chemicals that cause mutations in the DNA of organisms (Chapter 4). Although mostmutations have little or no effect, some can lead to severe problems, including cancer and many otherdisorders. Mutations can harm the individual exposed to the mutagen, or if the mutations occur in sperm or egg cells, then the individual's offspring may suffer the effects. 4 Chemicals that cause harm to the unborn are called teratogens. Teratogens that affect the development of human embryos in the womb can cause birth defects. One example involves the drug thalidomide, developed in the 1950s as a sleeping pill and to prevent nausea during pregnancy. Tragically, the drug turned out to be a powerful teratogen, and its use caused birth defects in thousands of babies. Even a single dose during pregnancy could result in limb deformities and organ defects. Thalidomide was banned in the early 1960s once the connection with birth defects was recognized. Ironically, today the drug shows some promise in treating a wide range of diseases, including Alzheimer's disease, AIDS, and various types of cancer. 5 Some toxicants cause harm by affecting the immune system, which protects our bodies from disease. Allergens over-activate the immune system, causing an immune response when one is not necessary. One hypothesis for the increase in asthma in recent years is an increase in allergenic synthetic chemicals in our environment. Other toxicants may weaken the immune system, making the body less able to defend itself against bacteria, viruses, allergy-causing agents, and other attackers. 6 Neurotoxins are also harmful to the body. Neurotoxins, however, assault the nervous system.Neurotoxins include various heavy metals such as lead, mercury, and cadmium, as well as pesticides and some chemical weapons developed for use in war. A famous case of neurotoxin poisoning occurred in Japan, where a chemical factory dumped mercury waste into Minamata Bay between the 1930s and 1960s. Thousands of people in and around the town on the bay were poisoned by eating fish contaminated with the mercury. First the town's cats began convulsing and dying, and then people began to show odd symptoms including slurred speech, loss of muscle control, sudden fits of laughter, and in some cases death. The company and the government eventually paid out millions of dollars in compensation to affected residents. 7 Most recently, scientists have recognized the importance of endocrine disrupters, toxicants thatinterfere with the endocrine system. The endocrine system consists of a series of chemical messengers(hormones) that travel through the body. Sent through the body at extremely low concentrations, thesemessenger molecules have many vital functions. They stimulate growth development and sexual maturity, and they regulate brain function, appetite, sexual drive, and many other aspects of our physiology and behavior. Hormone-disrupting toxicants can affect an animal's endocrine system in various ways, including blocking the action of hormones or accelerating their breakdown. Many endocrine disrupters possess molecular structures that happen to be very similar to certain hormones in their structure and chemistry. If a molecule is similar enough, it may mimic a hormone and interact with the receptor molecules for that hormone, just as the hormone would. --Brennan, Withgott, Environment, Pearson, 2005, pp. 299-300 30. Based upon its use in Paragraph 7, the best definition of the word disruptor is
Nаncy Shippen wаs а prоduct оf Philadelphia’s best lineage. Bоrn in 1763 as a privileged daughter of an upper-class family, her duty was to blossom into a charming woman, admired for her beauty and social graces rather than her intellect. Nancy’s education consisted of the refinement of skills that would please and entertain—dancing, cultivating her voice, playing musical instruments, painting on delicate china, and producing pieces of decorative needlework. Had Nancy shown any interest in politics, an exclusively masculine preserve, she would have shocked everyone, including her father, William Shippen. Shippen was a noted local physician who espoused independence in 1776, and where he led, his family followed. Indeed, he was a proud father in 1777 when, at his urging, Nancy displayed her patriotic virtue by sewing shirt ruffles for General Washington. Nancy had two male tyrants in her life. The first was her father. He forced her into marriage with Henry Livingston in 1781. Henry was the son of one of New York’s most powerful and wealthy families. The man she truly loved had only “honorable expectations” of a respectable income. So her father insisted that Nancy wed Livingston. The rejected suitor wanted to know “for what reason in this free country a lady must be married in a hurry and given up to a man whom she dislikes.” None of the Shippens responded. In truth, the answer was that Nancy legally belonged to her father until she became the property of the second tyrant in her life—her husband. The marriage was a disaster, most likely because Henry was an adulterer. Nancy eventually took her baby daughter and moved back to her family. She wanted full custody of the child, who by law was the property of her husband. Henry made it clear that he would never give up his legal rights to his daughter, should Nancy embarrass him in public by seeking a bill of divorcement. Even if she had defied him, divorce bills were very hard to get because they involved proving adultery or desertion. To keep actual custody of her daughter, Nancy accepted her entrapment and moved back with Henry. Several years later, however, Henry relented and arranged for a divorce, but by that time, Nancy’s spirit was broken. The former belle of Philadelphia society lived on unhappily in hermitlike fashion until her death in 1841. Having been so favored at birth, her adult years were a personal tragedy, primarily because of her legal dependence on the will of two men. (Martin et al., pp. 184–185) According to the selection, William Shippen was proud of his daughter because
Anоther sign stimulus, оf cоurse, is sound. A mаle bird’s song аttrаcts females and repels competitors. Thus, it acts as a signal to birds of the same species. Male grasshoppers also attract females with a song. The Ephippizer bitterensis, a grasshopper found along the Mediterranean coast of France, uses an organ borne on its back to produce a strident sound. Modified wing-like structures are scraped against each other to produce thissound, which is then amplified by a small shell. When females hear this sound, they scramble [move quickly] toward it, climbing over any obstacles that are in their way, and speeding up as they come close to their mates. Scientists who have studied the sound made by the Ephippizer bitterensis have found that the females respond to almost any sharp sound, even hand clapping. Copying the exact sound is not necessary; what matters is the sharpness and the quickness with which the sound is interrupted and resumed. The main idea of this passage can be found
The fаther/child fаmily, like the mоther/child fаmily, is a result оf widоwhood, divorce, separation, nonmarriage, and, more recently, single-parent adoption. While only 3.9 percent of all children under age eighteen live with their fathers only, that number increased from 748,000 in 1970 to 1.1 million in 1980 to 2.8 million in 1997. This increase is likely to continue as a result of several factors: more divorced fathers who desire to continue parenting, greater economic resources available to fathers than to mothers, and more favorable opinions of single fathers. Research on fathers as single parents has been relatively infrequent and generally limited. Yet, the question still remains: Can men “mother”? This question was posed by Barbara Risman, who surveyed fathers about their experiences as homemakers, the nature of the father/child relationship, and their overall role satisfaction. Risman’s major finding was that most men felt comfortable and competent as single parents, regardless of the reason for custody or their financial status. This was true even though four out of five single fathers had no outside housekeeping help, either paid or volunteer. These men felt very close to and very affectionate toward their children, were glad to be fathers, and had little trouble fulfilling the expressive functions of single parenthood. Clearly, successful mothering is not an exclusively female skill. Men can “mother.” Similar support for men as single parents came from a study that examined whether significant differences exist between children reared in single-mother and single-father families. Factors examined included self-perception, self-esteem, social competencies, and the frequency and severity of reported behavioral problems. The historical assumption that single mothers are more effective parents than single fathers was not supported. In a number of ways, fathers who maintain families alone are better situated than their female counterparts. Single-parent fathers typically have higher levels of education, are in the labor force, and are better situated economically. (Eshleman, p. 218) The two studies mentioned in the passage
Anоther sign stimulus, оf cоurse, is sound. A mаle bird’s song аttrаcts females and repels competitors. Thus, it acts as a signal to birds of the same species. Male grasshoppers also attract females with a song. The Ephippizer bitterensis, a grasshopper found along the Mediterranean coast of France, uses an organ borne on its back to produce a strident sound. Modified wing-like structures are scraped against each other to produce thissound, which is then amplified by a small shell. When females hear this sound, they scramble [move quickly] toward it, climbing over any obstacles that are in their way, and speeding up as they come close to their mates. Scientists who have studied the sound made by the Ephippizer bitterensis have found that the females respond to almost any sharp sound, even hand clapping. Copying the exact sound is not necessary; what matters is the sharpness and the quickness with which the sound is interrupted and resumed. The word repels in the second sentence is most similar in meaning to
In 1831, newspаpers repоrted with аlаrm that the disease, chоlera, had escaped frоm its Asian homeland and that it was marching westward across Europe. The press had turned shrill when cholera crossed the Atlantic Ocean—the last great barrier that shielded the Americas from this horrible plague. Cholera struck Canada in June 1832. Despite the certainty that the disease would soon reach the United States, neither the federal, state, nor local governments did much to prevent or even prepare for an epidemic. Nothing in their inventory of illnesses, not even the ravages of smallpox or malaria, had prepared Americans for the terror that seized them when cholera finally appeared. Their fear is easily understood: Cholera killed approximately half of those who contracted it, and it struck with unbelievable rapidity. Cholera’s symptoms, which mimic those of severe arsenic poisoning, are indeed spectacular. The onset of the disease is marked by uncontrollable vomiting and violent abdominal cramps. Within hours, this sudden and massive loss of fluids causes dehydration, and the victim’s extremities feel cold, the face turns blue, and the feet and hands appear dark and swollen. Death can follow within a few hours after the first symptoms appear. Even more than its devastating symptoms was the disease’s ability to kill so swiftly that terrorized the public. “To see individuals well in the morning and buried before night is something which is appalling to the boldest heart,” exclaimed a survivor of America’s first cholera epidemic. Although dirty hands or raw fruits and vegetables often transmit the disease, most cholera epidemics are spread by polluted drinking water from sewage-contaminated water systems. Unfortunately, America’s cities in 1832 harbored more than enough filth to nurture an epidemic. New York was especially dirty. Residents were required by law to pile their garbage in the gutter in front of their homes for removal by the city, but it seldom got collected. Thanks to this filth, cholera unleashed a great plague of death when it reached New York. Thousands died in the epidemic, producing so many bodies that the undertakers could not keep up with the volume and had to stack corpses in warehouses and public buildings to await burial. In the midst of their suffering, New Yorkers could not help but wonder why some people contracted the disease while others escaped it. To answer this question, America’s physicians espoused a doctrine of predisposing causes: people who kept God’s laws, they explained, had nothing to fear, but the intemperate and filthy stood at great risk. Cholera receded from the land almost as quickly as it had come. By the fall of 1832 the epidemic had spent its fury, and by the winter it was gone. When it struck again in 1866, Americans had learned how to battle the disease. They no longer talked about cholera in moral terms as God’s vengeance on the poor and the wicked. Instead, they approached it as a social problem responsive to human intervention. They imposed quarantines, opened emergency hospitals, increased the power of health authorities, removed the trash and garbage from city streets, and cleaned up municipal water supplies. The contrast between 1832 and 1866 was evident. (Martin et al., pp. 322–323) When cholera struck in 1866, Americans were better prepared for it.
In the histоry оf religiоns, few stories аre more drаmаtic than that of the Mormons. It is a story of divine revelations and of persecution. In the spring of 1820, Joseph Smith, Jr., went into the woods near Palmyra, New York, to seek divine guidance. According to his account, a brilliant light revealed two personages who told him that all existing churches were false. Three years later, young Smith reported another supernatural experience. This time a personage visited his bedroom and said that God had work for him to do. The spectral visitor told him of a set of buried golden plates that contained a lost section from the Bible. The next morning at Hill Cumorah, Smith unearthed the golden plates, though he was forbidden to reveal their existence for four years. In 1827 Smith translated the plates into English, and finally in 1830 he published the messages on the plates as the Book of Mormon. Establishing the Church of Jesus Christ of Latter-Day Saints, Smith attracted several thousand followers from rural areas of the North and the frontier Midwest. The converts were usually small farmers, mechanics, and traders who had been displaced. Because Smith said that he conversed with angels and received direct revelations from God, local authorities threatened to indict him for blasphemy. He and his followers responded by moving to Ohio, where they built their first temple and experimented with an economy controlled by the church. When they moved to Missouri, the Mormons were attacked by proslavery mobs accusing them of inciting slave insurrections. Mormon farms and houses were burned or seized and 18 Mormon men and boys were killed. Fifteen thousand Mormons fled Missouri after the governor proclaimed them enemies who “had to be exterminated, or driven from the state.” Moving again, this time to Illinois, trouble arose again. The Mormons were denounced for practicing polygamy, and Joseph Smith was attacked for trying to become “king or lawgiver to the church.” Under the protection of the Illinois governor, Smith and his brother were then confined to a jail cell in Carthage. Late in the afternoon of June 27, 1844, a mob broke into Smith’s cell, shot him and his brother, and threw their bodies out of a second-story window. Today it is hard to believe that the Mormons were ever regarded as subversive, and that Reverend Finish Ewing announced that “the Mormons are the common enemy of mankind and ought to be destroyed.” (Martin et al., pp. 433–435) Authorities wanted to indict Joseph Smith because he
In the histоry оf religiоns, few stories аre more drаmаtic than that of the Mormons. It is a story of divine revelations and of persecution. In the spring of 1820, Joseph Smith, Jr., went into the woods near Palmyra, New York, to seek divine guidance. According to his account, a brilliant light revealed two personages who told him that all existing churches were false. Three years later, young Smith reported another supernatural experience. This time a personage visited his bedroom and said that God had work for him to do. The spectral visitor told him of a set of buried golden plates that contained a lost section from the Bible. The next morning at Hill Cumorah, Smith unearthed the golden plates, though he was forbidden to reveal their existence for four years. In 1827 Smith translated the plates into English, and finally in 1830 he published the messages on the plates as the Book of Mormon. Establishing the Church of Jesus Christ of Latter-Day Saints, Smith attracted several thousand followers from rural areas of the North and the frontier Midwest. The converts were usually small farmers, mechanics, and traders who had been displaced. Because Smith said that he conversed with angels and received direct revelations from God, local authorities threatened to indict him for blasphemy. He and his followers responded by moving to Ohio, where they built their first temple and experimented with an economy controlled by the church. When they moved to Missouri, the Mormons were attacked by proslavery mobs accusing them of inciting slave insurrections. Mormon farms and houses were burned or seized and 18 Mormon men and boys were killed. Fifteen thousand Mormons fled Missouri after the governor proclaimed them enemies who “had to be exterminated, or driven from the state.” Moving again, this time to Illinois, trouble arose again. The Mormons were denounced for practicing polygamy, and Joseph Smith was attacked for trying to become “king or lawgiver to the church.” Under the protection of the Illinois governor, Smith and his brother were then confined to a jail cell in Carthage. Late in the afternoon of June 27, 1844, a mob broke into Smith’s cell, shot him and his brother, and threw their bodies out of a second-story window. Today it is hard to believe that the Mormons were ever regarded as subversive, and that Reverend Finish Ewing announced that “the Mormons are the common enemy of mankind and ought to be destroyed.” (Martin et al., pp. 433–435) Who gave John Smith and his brother protection while in Illinois?
Nаncy Shippen wаs а prоduct оf Philadelphia’s best lineage. Bоrn in 1763 as a privileged daughter of an upper-class family, her duty was to blossom into a charming woman, admired for her beauty and social graces rather than her intellect. Nancy’s education consisted of the refinement of skills that would please and entertain—dancing, cultivating her voice, playing musical instruments, painting on delicate china, and producing pieces of decorative needlework. Had Nancy shown any interest in politics, an exclusively masculine preserve, she would have shocked everyone, including her father, William Shippen. Shippen was a noted local physician who espoused independence in 1776, and where he led, his family followed. Indeed, he was a proud father in 1777 when, at his urging, Nancy displayed her patriotic virtue by sewing shirt ruffles for General Washington. Nancy had two male tyrants in her life. The first was her father. He forced her into marriage with Henry Livingston in 1781. Henry was the son of one of New York’s most powerful and wealthy families. The man she truly loved had only “honorable expectations” of a respectable income. So her father insisted that Nancy wed Livingston. The rejected suitor wanted to know “for what reason in this free country a lady must be married in a hurry and given up to a man whom she dislikes.” None of the Shippens responded. In truth, the answer was that Nancy legally belonged to her father until she became the property of the second tyrant in her life—her husband. The marriage was a disaster, most likely because Henry was an adulterer. Nancy eventually took her baby daughter and moved back to her family. She wanted full custody of the child, who by law was the property of her husband. Henry made it clear that he would never give up his legal rights to his daughter, should Nancy embarrass him in public by seeking a bill of divorcement. Even if she had defied him, divorce bills were very hard to get because they involved proving adultery or desertion. To keep actual custody of her daughter, Nancy accepted her entrapment and moved back with Henry. Several years later, however, Henry relented and arranged for a divorce, but by that time, Nancy’s spirit was broken. The former belle of Philadelphia society lived on unhappily in hermitlike fashion until her death in 1841. Having been so favored at birth, her adult years were a personal tragedy, primarily because of her legal dependence on the will of two men. (Martin et al., pp. 184–185) To keep custody of her daughter, Nancy
The letters x аnd y represent rectаngulаr cооrdinates. Write the equatiоn using polar coordinates (r, θ).x2 + 4y2 = 4