问题 选择题

豌豆、小麦的传粉方式是(  )

A.自花传粉

B.异花传粉

C.风力传粉

D.昆虫传粉

答案

答案:A

题目分析:雄蕊花药里的花粉落到雌蕊柱头上的过程叫做受粉,又叫做传粉,有自花传粉和异花传粉两种方式,两性花可以进行自花传粉,单性花只能进行异花传粉,花粉落到同一朵花的柱头上的传粉方式为自花传粉,花粉借助外力,从一朵花的雄蕊落到另一朵花的雌蕊柱头上的过程,叫做异花传粉,传粉根据借助外力的不同,花可以分为虫媒花与风媒花,靠昆虫等传粉的花叫虫媒花,靠风力传粉的花叫风媒花,小麦和豌豆,属于两性花,它在开花前就完成了受精作用,因为受精是在传粉之后的过程,传粉过程是在同一朵花里进行的,故属于自花传粉。

点评:此题为基础题,解答此题的关键是正确区别自花传粉与异花传粉这两个概念。

阅读理解

Goats are being hired to do the work of people near SanDiego. The fires that occurred in Hillborbough four years ago destroyed thirty homes, most of which have been rebuilt. While people were rebuilding the homes, the grasses and bushes were growing back. The area is now so overgrown in bushes that there is again a major danger of fire.

The city council asked for offers to remove the bushes. The lowest bid they received was $50,000-----and that was if the city provided breakfast and lunch for the workers for thr six weeks it would take to clear the overgrown area. The city only wanted to give unlimited coffee and a piece of bread a day for each person. When that offer was rejected, the city asked for help on its website.

A sheepherder(养绵羊的人) in Montanta and a goatherder(养山羊的人) in San Bernardino read about the city’s plight (困境)while surfing the Web on their laptops. They both offered to do the job for $25,000. The council chosed the goatherder because he lived closer. When he was told that the city dump(垃圾场) was overflowing , the gotherder said, “No problem. My goats will eat everything in your dump, except the car engines, of course.” So ,for another $5,000, the city killed two birds with one stone. If all goes well, they will invite the goatherder and his “family” back every three years. The goatherder said that he would probably visit San Diego while his goats were in the dump. “I want to go there by plane, I just hope we don’t crash. My goats will miss me a lot.” He said.

小题1:Why did the city council want to remove the bush?

A.Because the fires in hillborbough destroyed 30 homes.

B.Because people wanted to build their homes there.

C.Because the overgrown bushes could cause fires again.

D.Because two sheeherder offered to do the job.小题2:The goatherder was chosen to do the job because       

A.He offered to do it for the lower price

B.It was easier to transport his goat

C.Goats can do the job better than the job

D.The city wanted to raise more goats小题3:According to the passage,          

A.the sheepherder offered to do the job for $50.000

B.the lowest bid to remove the bushes was $50,000

C.the sheepherder and the goatherder were both addicted to surfing the Internet.

D.hiring goats to do the job saved the government lots of money.小题4: we can infer from the passage that          

A.the city will remove the bushes in this area regularly

B.the goatherder asked for $50,000 to kill the birds with stones.

C.the goatherder was invited to San Diego to do some sightseeing.

D.the city council was not kind to the people who worked for it.

单项选择题