问题 单项选择题

下列关于生物多样性的说法正确的是()

A.外来物种引入不一定能增加生物的多样性

B.新物种的诞生丰富的是遗传多样性

C.生物圈内所有的生物一起构成了生物多样性

D.某种动物的直毛基因占基因库中所有基因的比值为直毛基因频率

答案

参考答案:A

解析:

生物多样性包括基因多样性、物种多样性和生态系统多样性,新物种的诞生丰富的是物种多样性多样性,B错误。生物多样性是指生物圈中的所有植物,动物和微生物,它们所拥有的全部基因以及各种各样的生态系统,C错误;一个种群中全部个体所含有的全部基因,叫做这个种群的基因库,在一个种群基因库中,某个基因占全部等位基因的比率,叫做基因频率,所以D错误。

考点:本题旨在考查生物多样性保护的意义和措施,意在考查能理解所学知识的要点。

阅读理解

Iodine (碘)– rich salt was the hottest item on Chinese shelves Thursday, being snapped up (抢购) by shoppers after rumors spread that iodine intake could help protect one’s body from radiation damage, although the authorities have confirmed that the nuclear crisis in Japan had not affected China.

Rumors also spread about radioactive substances being leaked into ocean water that could pollute Chinese coasts.

The crazy buying has occurred nationwide, from the supposedly easily – harmed eastern coastal provinces to regions far – inland such as Xinjiang.

Supermarkets and convenience stores began reporting the lack of salt stocks from early Wednesday, with all salt sold out at many Carrefour and Wal – Mart stores. Some online clothes stores have begun offering salt as a bonus to customers.

Relevant government departments were trying hard to stop this round of panic – buying.

The Ministry of Health deniedthe rumor that eating more iodine – rich salt could repair damage from radiation, saying that it is technically impossible to absorb enough iodine for radiation prevention from eating salt.

The government urges the local market authorities to keep all salt sellers in check and to prevent storing and overpricing.

Also the spokesman of the government said that China’s seawater, as a source of salt, would not be affected by the nuclear crisis, as it would be impossible for radioactive substances to reach Chinese waters via the eastward ocean current.

“Reasons behind the salt rush include unclear information on the development of the nuclear crisis and terrifying media reports of the severity of a possible complete meltdown. If the fear of a Chernobyl – like catastrophe cannot be ended, the crazy buying will likely continue,” said a professor from Beijing University.

Beijing urged Tokyo Thursday to better release information at the Fukushima plant.

小题1:What caused the crazy buying of iodine – rich salt?

A.The rumor caused by the unclear information.

B.The shortage of iodine – rich salt in stores.

C.The multi – functions of iodine in salt.

D.The richness of iodine in salt in China.小题2:Some online clothes stores began offering salt as a bonus to customers because _______.

A.they can increase their sales by doing so      B.the salt from them is more effective

C.the customers prefer to buy salt on line       D.the salt from the on-line store is free

小题3:It’s quite clear that some sellers want to store iodine-rich salt is to _______.

A.increase the sales of related products

B.raise the price of products online

C.make more money from it

D.meet the needs of the market小题4:Why is it impossible for radioactive substances to reach Chinese waters?

A.The ocean is really too large.

B.The distance from Japan is too far.

C.The nuclear pollution is not so serious.

D.The ocean current is eastward.小题5:Which of the following should be the best title of the passage?

A.Panic Salt Buying Creates Bitter Crisis

B.Effect of the Terrible Disaster in Japan

C.A Rumor Throughout the Country.

D.Iodine-rich Salt Prevents Radiation.

单项选择题