问答题gene pool

问答题(46) Many journalism critics have recently argued that American journalism is undergoing a profound change because it now regularly mixes entertainment with the news. Critics typically argue that this entertainment is in the form of sensationalistic celebrity-scandal. In fact, there is a long history of sensationalism in American journalism, a fact documented by several journalism historians. (47) But the main point of contemporary critics is that sensationalism and tabloid-style techniques, which were always present on the fringes of journalism, are now becoming the norm in American journalism, and are being adopted by so-called "mainstream" media as part of economic survival strategies in the cutthroat business climate of American mass media. These contemporary critics typically argue that there should be a rigid boundary between mainstream journalism and other kinds of mass communication such as tabloid journalism. (48) The critics imply that one kind of communication is more legitimate in certain contexts than the other, and even that tabloid journalism is not journalism at all but is instead entertainment. One of the claims made by mass media critics is that journalism just recently got worse. But this may be a perennial complaint. (49) A quick review of journalism criticism reveals that the argument that journalism used to be better but just recently got worse is common throughout the history of journalism. The critiques usually say that journalism used to make bold distinctions between news and entertainment but now combines the two. These critiques construct the logical conclusion that journalism has steadily declined in quality over many years. (50) Taken together, the criticisms add up to the conclusions that the people who used to do journalism were better and had higher standards than those of today and that the distinctions between news and entertainment used to be greater. Examples of this critique can be found in even the earliest discussions of American journalism. For instance, critics panned Benjamin Day's New York Sun of the early 1830s because it often contained humor and sensational news of suicides. Similarly, some critics hated James Gordon Bennett's New York Herald of the mid-to late-1830s because it contained entertaining satirically written police court reports, as well as in-depth crime stories. Bennett pioneered the "human-interest story" or feature story when he wrote in vivid detail in 1836 about the grisly murder of the prostitute Helen Jewett, quoting her madam and describing Jewett's apartment in minute detail. Bennett's day-by-day narrative of the ensuing sensational trial reminds us of how journalism and entertaining literature have been combined for many years to make newsworthy stories "more palatable for consumption. " Bennett was soundly criticized by his competitors and others for blurring the boundary between journalism and entertainment. His detractors, many of them his competitors, waged what they called a "Moral War" in the late 1830s against Bennett and his enjoyable but sensationalistic newspaper. They maintained that Bennett was a "deviant" journalist because he blurred the boundaries of journalism by making his newspaper entertaining and popular. Those running the "Moral War" against Bennett were unsuccessful at running him out of the journalism business, but they did seriously wound his business.

问答题增强子具有哪些特点?

问答题Psychologists once believed that the motive that caused men to strive to attain high-level managerial positions was the "need for achievement". But now they believe it is the "need for power". Power seekers strive hard to reach positions where they can exercise authority over large numbers of people. (46) Individual performers who lack this drive are not likely to advance far up the managerial ladder. They usually scorn company politics and devote their energies to other types of activities. The power game is part of management, and it is played best by those who enjoy it most. (47) One of the least rational acts of business organizations is that of hiring managers who have a high need to exercise authority, and then teaching them that authoritative methods are wrong and that they should be consultative or participative. (48) It is a serious mistake to teach managers that they should adopt styles that are inconsistent with their unique personalities. Yet this is precisely what a large number of business organizations are doing; and it explains, in part, why their management development programs are not effective. (49) What managerial aspirants should be taught is how to exercise their authority in a way that is appropriate to the situation and the people involved. They need to learn that the real source of their power is their own knowledge and skill, and the strength of their own personalities, not the authority conferred on them by their positions. When they lack the knowledge or skill required to perform the work, they need to know how to share their authority. (50) But when they know what has to be done and have the skill and personality to get it done, they must exercise their traditional authority in whatever way is necessary.

问答题营养缺陷型

问答题为了弄清某种重要生命现象(性状)的分子机制，分子遗传学家通常首先进行遗传学研究，即诱变并筛选该生命现象(性状)发生改变的突变体。然而在实际工作中，经常不能获得预期中的突变体。试解释之。

问答题从现有科学事实，怎样正确理解在遗传中细胞核与细胞质之间的关系?

问答题顺反效应

问答题遗传漂变

问答题中国人的姓氏除少数外都是随父亲的，有人提出在中国人的群体遗传分析中将姓氏作为Y染色体的遗传标记进行研究，你觉得是可行的吗?为什么?请你比较姓氏的传递与Y染色体上基因传递的异同。

问答题将大肠杆菌培养在以甘油为惟一碳源的低限培养基中，lac操纵子表达吗?加入乳糖之后呢?除了乳糖，还加葡萄糖吗?为什么?

问答题BAC文库

问答题双线期

问答题染色质

问答题Directions: Write a letter to Prof. Wang, Head of Foreign Languages. Department, introducing to him your student Miss Jin Hua. You should write about 100 words on ANSWER SHEET 2. Do not sign your own name at the end of the letter. Use "Li Ming" instead. Do not write the address.

问答题雌性胎生哺乳动物细胞中两条X染色体中的一条在发育早期随机失活，请说明：

问答题简述转导、接合和转化三种重组机制有何异同?相对而言目前对哪一种机制了解最少?

问答题中心法则

问答题顺反子(cistron)

问答题以乳糖操纵子(lac operon，由lacI、lacP、lacO、lacZ、lacY及lacA组成)为例，说明何为顺式作用因子(cis-element)和反式作用因子(trans-element)，以及它们各自如何起作用。