问题 填空题 案例分析题

某生物兴趣小组的同学利用本校连续四年来全体学生的体检结果对全体学生进行红绿色盲发病情况的调查,结果汇总如下表,请根据表中数据分析回答:

第2组同学希望了解红绿色盲症的(),所以调查色盲男生甲的家族遗传病史,记录如下:男生甲的外祖父为红绿色盲,但其外祖母、祖父母、父母均正常。请问:男生甲的

家族中色盲基因的传递途径是:外祖父→()→男生本人,这种传递特点在遗传学上称为()

答案

参考答案:遗传方式;母亲;交叉遗传(隔代遗传)

单项选择题
单项选择题

Questions 91 — 100 are based on the following passage. (15 points)Electronic mail has become an extremely important and popular means of communication.The convenience and efficiency of electronic mail are threatened by the extremely rapid growth in the volume of unsolicited commercial electronic mail. Unsolicited commercial electronic mail is currently estimated to account for over half of all electronic mail traffic, up from an estimated 7 percent in 2001, and the volume continues to rise. Most of these messages are fraudulent or deceptive in one or more respects.The receipt of unsolicited commercial electronic mail may result in costs to recipients who cannot refuse to accept such mail and who incur costs for the storage of such mail, or for the time spent accessing, reviewing, and discarding such mail, or for both. The receipt of a large number of unwanted messages also decreases the convenience of electronic mail and creates a risk that wanted electronic mail messages, both commercial and noncommercial, will be lost, overlooked, or discarded amidst the larger volume of unwanted messages, thus reducing the reliability and usefulness of electronic mail to the recipient. Some commercial electronic mail contains material that many recipients may consider vulgar or pornographic in nature.The growth in unsolicited commercial electronic mail imposes significant monetary costs on providers of Internet access services, businesses, and educational and nonprofit institutions that carry and receive such mail, as there is a finite volume of mail that such providers, businesses, and institutions can handle without further investment in infrastructure. Many senders of unsolicited commercial electronic mail purposefully disguise the source of such mail.Many senders of unsolicited commercial electronic mail purposefully include misleading information in the messages’’ subject lines in order to induce the recipients to view the messages. While some senders of commercial electronic mail messages provide simple and reliable ways for recipients to reject (or ’’opt-out’’ of) receipt of commercial electronic mail from such senders in the future, other senders provide no such ’’opt-out’’ mechanism, or refuse to honor the requests of recipients not to receive electronic mail from such senders in the future, or both.Many senders of bulk unsolicited commercial electronic mail use computer programs to gather large numbers of electronic mail addresses on an automated basis from Internet websites or online services where users must post their addresses in order to make full use of the website or service.The problems associated with the rapid growth and abuse of unsolicited commercial electronic mail cannot be solved by the government alone. The development and adoption of technological approaches and the pursuit of cooperative efforts with other countries will be necessary as well.

Disguise in Paragraph 4 is closest in meaning to________.

A.reveal

B.hide

C.deliver

D.post