Question

Plants may not have eyes and ears，but they can recognize their siblings (兄弟姐妹)，and researchers at the University of Delaware have discovered how.The ID system lies in the roots and the chemical signals they secrete (分泌)．

Canadian researchers published that sea rocket，a common seashore plant，can recognize its siblings.Susan Dudley observed that when siblings are grown next to each other in the soil，they “play nice” and don’t send out more roots to compete.However，the moment one of the plants is thrown in with strangers，it begins competing with them by rapidly growing more roots to take up the water and mineral nutrients in the soil.

After reading Dudley’s study，Bais decided to find the method behind the sibling recognition.Working in his laboratory，Bais and his doctoral student Meredith Biedrzycki set up a study with wild populations of Arabidopsis thaliana.In a series of experiments，young seedlings were exposed to liquid media containing the root secretions from siblings，from strangers，or only their own secretions.The length of the longest lateral (侧面的) root was measured.The exposure of plants to the root secretions of strangers induced (引诱) greater lateral root formation than exposure of plants to sibling secretions.Strangers planted next to each other are often shorter，because so much of their energy is directed at root growth.Because siblings aren’t competing against each other，their roots are often much shallower (浅的)．

Biedrzycki did the painstaking laboratory research，observing more than 3,000 plants involved in the study every day for seven continuous days and documenting the root patterns.“Arabidopsis roots are nearly translucent (半透明的) when they are young and were also twisted when I removed them from plates，”Biedrzycki notes.“This manuscript (手稿) is very important for my research since the focus of my thesis project is understanding the biochemical ways behind root secretions.”

The research also may have implications for the home gardener.“Often we’ll put plants in the ground next to each other and when they don’t do well，we blame the local garden center where we bought them or we attribute their failure to a germ，”Bais says.“But maybe there’s more to it than that.”

1.Which of the following would be the best title for this passage?

A．A Great Biology Researcher

B．Plants Recognize Their Siblings

C．Plants’ Roots and Secretions

D．A Research on Plants

2. What encouraged Bais to study the sibling recognition?

A．Sea rocket.

B．Plants’ sensing system.

C．Biedrzycki’s thesis project.

D．Dudley’s study.

3. What does the underlined word “painstaking” in Paragraph 4 probably mean?

A．Important.  B．Adventurous.

C．Careful.  D．Hard­working.

4.What can we infer from the last paragraph?

A．The local garden center should be blamed when plants can’t grow well.

B．The local garden center often sells low quality seeds to customers.

C．Plants in the home garden can’t grow well because of the germ and seeds.

D．Competing against strangers，plants in the home garden can’t grow well.

Answer

1.B

2.D

3.D

4.D

【解析】

1.

解析 标题归纳题。文章第一段第一句就开篇点题，植物可能没有眼睛和耳朵，但他们认识自己的“兄弟姐妹”。下面所有内容都是围绕这一中心展开的。

2.2】 D

解析 细节理解题。根据第三段第一句可知，在看了Dudley的研究发现后，Bais决定找出植物识别同胞的方法，故D项正确。

3.3】 D

解析 词义猜测题。文章第四段第一句指出，Biedrzycki连续花费7天时间来研究、观察3 000多种植物，由此推知painstaking为hard­working之意。

4.4】 D

解析 推理判断题。在文章最后一段作者提到，当家中花园里的植物生长得不好的时候，人们经常会责怪花卉商店或者认为细菌太多。而最后一句作者又暗示，花园里面的植物生长得不好有可能是因为花园里种植了不同种类的植物，它们之间相互竞争，注重根部的生长，从而生长得不好。