问题 实验题

为了验证某大豆品种的矮化特性与赤霉素的含量有关,请用所给的实验材料,完成下列实验步骤并回答问题:

实验材料:具2片真叶且长势相同的该品种大豆幼苗若干、完全培养液、蒸馏水、适宜浓度的赤霉素溶液、喷壶等。

(1)实验步骤:

①.将上述大豆幼苗平均分成A、B两组,A组为对照组,B组为实验组,分别置于等量的完全培养液中培养。

②.用喷壶分别将_______和_______喷洒在A、B两组幼苗上。

③.将两组幼苗置于相同且适宜的温度和光照等条件下培养,一段时间后,测定两组植株的_________。

(2)预测实验结果:_________________________。

(3)上述试验中,如果A、B两组各选用1株幼苗进行实验,是否影响实验结果的可靠性?为什么?______。

(4)该实验原理是___________________________。

答案

(1)②.蒸馏水   赤霉素溶液   ③.高度

(2)A组(对照组)植株的平均高度小于B组(实验组)植株的平均高度

(3)有影响。   因为每组实验材料的数量过少(或样本数过少),代表性差

(4)赤霉素有促进细胞伸长使植株增高的作用。用赤霉素处理植株后,可以显著增加植株的高度,据此可以验证该大豆品种的矮化特性与赤霉素的含量有关

单项选择题

In its everyday life, Italy is very much the man’s world. However, because of the Italian’s understanding of foreigners, the woman tourist is able to invade many of the male places that are prohibited to Italian women. These places include the cafè and the wine shop.

In the large cities the cafè is a combination of club and office. Here, for the price of a coffee, an Italian can read all the newspapers brought to him. And he can transact business, with the waiter producing pen, ink, and stamps as needed. Or if he wants, he can sit outside under a canvas covering before the door and enjoy the sight of beautiful women passing by.

The wine shop, as a rule, is a more vigorous place than the caf6, and is filled almost exclusively with men. Wandering singers, generally in groups of two or three, add to the noise of these places with their songs and music. Many of the songs are of a political character and make fun of the leading statesmen of Italy, America, England, France, and Russia. But the songs are generally showing off a spirit of mischief. And when the criticism is about America, the American tourists find themselves laughing as much as anyone else. The Italian is a master at making fun of you and making you like it.

The Italian men are deep-rooted gamblers. They have been brought up to it as children, but they are cautious gamblers and never go too much in it. The national lottery used to be one of the most popular forms of gambling. But later a football stake had taken away much of the interest in the lottery. But here the important thing is that gambling, the same as drinking, seldom goes to an Italian’s head and his bets are not really dangerous risks. Even at cards the Italian plays for low stakes, generally for a cup of coffee or wine.

In this world of the Italian male it would be careless if the romanticism of the Italian were neglected. The Italian might well be described as the world’s greatest romanticist. From any boat in Venice to any member of the government in Rome, the Italian is always aware of romance, of love and of the importance of being a good lover.

on the beaches of Italy, the visitor is aware that the Italian really live for romance. His manners, his compliments, his charm and his general way of behaving are those of a romanticist. Almost every Italian you meet is convinced that he is another Casanova.

Romance is as much a part of Italy as its art and its history. Perhaps the feeling of romance that wells up in you when you come to Italy is one of the greatest things that Italy has to offer a world that is tired of war and political intrigue. It is the ideal place for a honeymoon because hotel managers and waiters make you conscious of your own love and stress it in such a way that you feel more in love in this country than in any other.

Why did many Italians lose interest in lottery later?()

A.Because they found lottery too risky.

B.Because they realized that buying lottery is a waste of money.

C.Because they thought playing cards is more interesting.

D.Because they found the football stake more attractive.

单项选择题