问题 单项选择题

下图表示基因型为AaBb的玉米植株的四种生殖过程,从上到下依次为A、B、C、D过程。下列有关叙述中不正确的是()

A.A过程中获得单倍体植株的方法是花药离体培养,要使它能够产生可育后代,常采用一定浓度的秋水仙素处理幼苗,其作用机理是抑制细胞分裂过程中纺锤体的形成,使染色体数目加倍

B.B过程中,种子长成的植株具有更大的变异性

C.制备人工种子的关键一步是C过程中经脱分化、再分化阶段培育成具有生根发芽能力的胚状体

D.D过程中,经两个原生质体融合后形成的融合细胞内有2个染色体组

答案

参考答案:D

阅读理解

A butcher watching over his shop was really surprised when he saw a dog coming inside the shop. He went over to the dog and noticed it had a note in its mouth. He took the note and it read “Can I have 12 sausages and a leg of lamb, please. The dog has money in his mouth, as well.”

The butcher looked carefully and was surprised to find that there was really a ten-dollar note there. So he took the money and put the sausages and lamb in a bag, placing it in the dog’s mouth. The butcher was so impressed, and since it was about closing time, he decided to shut up shop and follow the dog.

So off he went. He followed the dog to a bus stop. The dog stopped and started looking at the timetable. The dog checked out the time, and then sat on one of the seats provided. Along came a bus. The dog walked around to the front, looked at the number, and went back to its seat. Another bus came. Again the dog went around to the front, looked at the number and climbed on. The butcher, by now, open-mouthed, followed it onto the bus.

The bus traveled through the town and out into the suburbs. Eventually the dog got up, and moved to the front of the bus. It stood on two back paws and pushed the button to stop the bus. Then it got off with groceries still in its mouth.

Well, the dog and the butcher were walking along the road, and then the dog turned into a house. It walked up the path, and dropped the groceries on the step. Then it walked back down the path, took a big run, and threw itself against the door. Then again, it threw himself against it. There’s no answer at the house. so the dog waited at the door.

The butcher watched as a big guy opened the door, and started shouting at it. The butcher ran up, and stopped the guy. “Why do you shout at the dog? It is really a genius.” The guy responded, “You call this clever? This is the second time this week that this stupid dog’s forgotten its key.”

小题1:Which may be the best title of the passage?

A.A clever dog.

B.A curious butcher.

C.A cruel owner.

D.A second lost key.小题2:Why was the butcher surprised when he saw the dog?

A.Because there was a note in the dog’s mouth.

B.Because a dog was not supposed to come into his shop alone.

C.Because the dog was not afraid of being butchered.

D.Because the dog could read.小题3:The passage implies that _________.

A.dogs are cleverer than man

B.dogs are our best friend

C.the butcher is a cruel person

D.some people are never satisfied with what they have got小题4:The dog threw itself against the door, because _________.

A.it wanted to force the door open

B.it wanted its owner to open the door

C.it wanted to punish itself for forgetting the key

D.it wanted to get the butcher’s help小题5:Which of the following statements is NOT true?

A.The butcher was curious so he followed the dog.

B.The dog didn’t get on the first bus because it was the wrong number.

C.To get off the bus, you should let the driver know by pressing the button.

D.The dog would be driven away by the big guy.

单项选择题 B1型题