试题与答案

狗体细胞内含有39对染色体,狗的毛色深浅与黑色素合成有关。B基因控制真黑色素合成

题型:填空题

题目:

狗体细胞内含有39对染色体,狗的毛色深浅与黑色素合成有关。B基因控制真黑色素合成,b基因控制浅黑色素合成,基因型为BB、Bb的狗分别表现为黑色、棕色,基因型为bb的狗表现为黄色。同时,狗的体色还受E、e基因的影响,当E存在时,真黑色素能够正常合成,e基因导致真黑色素不能合成,这两对基因分别位于第12号和第19号染色体上。请回答下列问题:

(1)这两对基因的遗传遵循孟德尔的_________定律。

(2)若有一只黑色狗与一只棕色狗杂交,子代中黑、棕、黄三种颜色的狗都有。则两亲本的基因型为_________、_________。子代中黄色狗的基因型为____________

(3)若第(2)小题中的两只狗再次杂交,生出一只黑色狗的概率是________,这只狗是纯合子的概率为________

(4)狗的长毛(D)对短毛(d)为完全显性,现有健康成年纯种的黑色短毛雌狗(BBdd)、黄色长毛雄狗(bbDD)各若干只,请通过杂交实验确定D、d和B、b两对基因是否都位于第12号染色体上。请补充下面实验内容。

实验步骤:

①.亲本:黑色短毛雌狗×黄色长毛雄狗→F1,表现型为________

②.F1发育至成年,从F1中选取多对健康的雌雄狗杂交得F2

③.统计F2中狗的毛色和毛长。

实验结果分析:若F2表现型及比例为____________,说明D、d基因不位于第12号染色体上;否则,说明D、d 基因位于第12号染色体上。

答案:

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Here’s a tale of two companies. Both are foreign owned, and both are embroiled in scandals involving allegations of sexual harassment. Company A is confronted with the problem and punishes top execs. Company B stonewalls and mounts an aggressive campaign to discredit its accusers and portray itself as a victim of slander.

(41)For business schools looking for a few good case studies in damage control, last week was about as good as it gets. One was Swedish pharmaceuticals company Astra USA, a maker of asthma medications and the popular anesthetic Xylocaine. Facing similar charges, Mitsubishi Motor manufacturing of America opted for in-your-face denial. Who did it right It’s too soon to know for sure. Astra’s strategy may seem smarter. Financially speaking, at least, one can see why Mitsubishi is reluctant to issue a public mea culpa. Fessing up could expose it to as much as $200 million in damages.

Such controversies are no rarity these days. The Equal Employment Opportunity commission alone received more than 15,000 complaints of sexual harassment last year, more than twice as many as in 1991. Its suit against Mitsubishi, filed last month, may turn out to be by far the biggest ever—and could eventually involve as many as two thirds of the company’s 900 female workers.

(42)Mitsubishi’s response was clear from the beginning. When the EEOC announced its case against the Illinois automaker, the company dispatched busloads of workers to picket the agency’s Chicago offices. Attorneys for Mitsubishi will no doubt probe the private lives of the women lodging complaints, and may even accuse them of " Japanbashing. " Mitsubishi’s brass in Tokyo seemed a bit taken aback by the ferocity of the counteroffensive, to the point of suggesting that maybe the case could be quietly settled.

(43)Could such tactics be effective If aggressive PR makes people doubt the allegations against the company, or encourages federal investigators to settle on more favorable terms, then the strategy will have succeeded. But there are risks, especially for consumer companies like Mitsubishi.

(44)That’s no small threat, considering that Mitsubishi is struggling to turn a profit in this country.

(45)Astra’s strategy seems savvier. Its openness and prompt response might help it evade punitive damages, should any of the complaints go to a jury. In fact, that may be a chief reason the company acted even before it completed its own investigation. That said, Astra is in the soup to begin with because it had no adequate mechanisms for reporting incidents, and because it failed to deal with its problems before they became public. Women have complained of harassment at the company for more than a decade. BusinessWeek reports incidents ranging from gropings at company retreats to suggestions that female sales reps could advance their careers by putting out sexually for their bosses—including the head of the company, Lars Bildman. (His lawyer denies the allegations, as do the other executives. ) So far, Astra itself has offered no evidence suggesting any of the three are guilty.

Both companies now promise to do better. Astra is overhauling its corporate personnel policies and plans to train managers on how to handle issues of sexual discrimination. So is Mitsubishi. Says the automaker’s general counsel Gary Shultz: " We are going to become the model in handling sexual-harassment and -discrimination cases. " That remains to be seen. If these sorts of scandals force companies to set up rules that actually work, that may be the best case study of all.

[A] That’s precisely what the company did in response to a prior sexual-harassment suit filed by 29 women in 1994.

[B] " A great deal of attention should be paid to these affairs, " says Mitsubishis’s spokesman.

[C] But " we’re taking these allegations very seriously, " says Astra spokesman Benjamin Kincannon.

[D] Outraged by the automaker’s seeming disregard of its problems, perennial presidential hopeful Jesse Jackson and the National Organization for Women called on car buyers to boycott the company.

[E] When Business Week published tales of wide-ranging abuse at Astra’s American subsidiary, outside Boston, the company quickly faced up to the problem and suspended its U. S. chief executive, along with two top lieutenants.

[F] Prof. Martin Stoller, a crisis-management expert at Northwestern University, thinks so. " The aim of crisis management is to stop the attackers, " he says.

[G] Astra and Mitsubishi have joined hand with each other to solve the problem of sexual harassment.

45()

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