问题 选择题

下列关于生物生殖发育的叙述中,正确的是(  )

①鸡属于晚成鸟,须由亲鸟育养

②菜粉蝶的发育属于完全变态发育

③营养生殖能够保持植物亲本的优良性状

④蝗虫的发育经历了受精卵、幼虫、成虫三个阶段

⑤要确保嫁接成功,必须把接穗和砧木的形成层结合在一起.

A.①②③④

B.①②③⑤

C.②③④⑤

D.①②④⑤

答案

①鸡的雏鸡,孵出时已充分发育,能独立生活,属于早成雏;家鸽在孵出时尚未充分发育,雏鸽需要由亲鸟育雏属于晚成雏.

②菜粉蝶的发育过程经过卵、幼虫、蛹和成虫4个时期,属于完全变态发育.

③营养生殖属于无性繁殖,没有精子和卵细胞结合成受精卵的过程,因而后代一般不会出现变异,能保持植物亲本的优良性状.

④蝗虫的幼虫和成虫的形态结构、生活习性相似,只是大小、翅膀有无、生殖器官发育成度不同,属于不完全变态发育;包括受精卵、幼虫和成虫三个时期.

⑤嫁接是指把一个植物体的芽或枝,接在另一个植物体上,使结合在一起的两部分长成一个完整的植物体.嫁接时,接上去的芽或枝叫接穗,被接的植物叫砧木,嫁接时应当使接穗和砧木的形成层紧密结合,以确保成活,因为形成层具有很强的分裂能力,能不断分裂产生新细胞,使得接穗和砧木长在一起,易于成活.

故选C.

阅读理解

                                     C

8:30 PM

Outlook

Outlook is back with a new series of reports to keep you up date with all that’s new in the world of entertainment. Stories go all the way from the technical to the romantic, from stage to screen. There will be reports of the stars of the moment, the stars of the future and the stars of the past. The director with his new film,he designer with the latest fashion and the musician with the popular song are part of the new Outlook . The program is introduced by Fran Levine.

9:00 PM

Discovery

When a 10-year-old boy gets a first class degree in mathematics or an 8-year-old plays chess like a future grand master, they are considered as geniuses . Where does the quality of genius come from? Is it all in the genes (基因) or can any child be turned into a genius ? And if parents do have a child who might become a genius in the future,what should they do? In this 30-minute film, Barry Johnson , the professor at School of Medicine , New York University will help you discover the answer .

10:00 P

Science/Health

Is it possible to beat high blood pressure without drugs? The answer is “yes”, according to the researchers at Johns Hopkins  and three other medical centers . After a study of 800 persons with high blood pressure , they found that after 6 months , those devoted to weight loss—exercise and eating a low—salt , low-fat food—lost about 13 pounds and became fitter . Plus , 35% of them dropped into the “normal” category(范畴). This week, Dr . Alan Duckworth will tell you how these people reduce their blood pressure to a level similar to what’s achieved with Hypertension drugs .

小题1:The main purpose of writing these three texts is        .

A.to invite people to see films

B.to invite people to topic discussions

C.to attract more students to attend lectures

D.to attract more people to watch TV programs小题2:From Outlook , you can get a great deal of information about          .

A.story tellers

B.famous stars

C.film companies

D.music fans小题3:Who will be most probably interested in Discovery ?

A.Parents who want to send their children to a school of medicine .

B.Children who are good at mathematics .

C.Parents who want their child to become another Albert Einstein .

D.Children who are interested in playing chess .小题4:In Science / Health; “Johns Hopkins” is             .

A.a famous university

B.a medical center

C.a well-known doctor

D.a drug company小题5:According to the third text , which of the following has almost the same effect as Hypertension drug ?

A.Exercise plus a healthy diet .

B.Loss of thirteen pounds in weight .

C.Six months of exercise without drugs .

D.Low-salt and low-fat food .

单项选择题