Question

It is easy for us to tell who our family members are, but do plants recognize(识别) their own family? Some do, scientists say, according to a report by Science News in early 2010.

Guillermo P. Murphy and Susan Dudley are two plant scientists from McMaster University in Hamilton, Canada. They did a few experiments with Jewelweeds, a kind of flower that grows in wet, shady spots. They found that the flowers seem to know their own flower family. In their experiments, Murphy and Dudley planted jewelweeds in pots with either siblings or strangers.

When jewelweeds were planted in pots with strangers, the plants started to grow more leaves than if they had been planted alone. This response(反应)suggests that plants are competing with strangers for sunlight, since a plant with more leaves can receive more light and make more food. Jewelweeds usually grow in the shade, where sunlight is not enough.

When jewelweed seedlings(幼苗)were planted with siblings, they grew a few more branches than they usually would if they were alone – but they did not start growing lots of extra leaves. This behavior suggests the plants are more likely to share resources, rather than compete.

According to the Science News report, Jewelweeds are not the first plants that plant scientists have studied for family recognition. In 2007, Dudley and her team studied the Great Lakes sea rocket, a plant that grows on the beach – where it may be hard to get fresh water. In that experiment, the scientists found that when sea rockets were planted with siblings, they tolerated each other. But when they were planted with strangers, the sea rockets reacted by working extra hard to grow lots of roots.

Dudley says this just because sea rockets, on the beach, get plenty of sun but struggle for water – so when they’re threatened, they compete for water. Jewelweeds have plenty of water but have to compete for sunshine, so they grow more leaves.

1. What does the underlined word siblings mean?

A．Flowers come from foreign countries.

B．Plants growing in different environments.

C．Flowers planted with lots of strangers.

D．Plants that are the same kind.

2. In the text, the writer mentioned the experiments of Jewelweeds to         .

A．make a comparison                      B．introduce a topic

C．describe a pretty flower                  D．build a new theory

3. According to the passage, flowers planted alone will         .

A．grow more leaves than those planted in groups

B．become taller than those with more branches

C．grow fewer leaves than those planted with strangers

D．become ill easily because they can’t get enough shade

4. What can be the best title for the passage?

A．New Discoveries about Plants

B．How Plants Compete with Each Other

C．Family Recognition among Plants

D．Jewelweeds and the Great Lakes Sea Rockets

Answer

1.D

2.B

3.C

4.C

【解析】

试题分析：这篇文章讲的是科学家通过做实验，发现将一种植物与不同种类的植物种植在一起，它会和其他植物竞争养分，将会长的更好，如果单独种植的话，则会分享资源，而不竞争。

1.推断题。由第二段最后一句In their experiments, Murphy and Dudley planted jewelweeds in pots with either siblings or strangers.在他们的实验中，Murphy and Dudley将凤仙花要么和同类植物种植在一起，要么和不同的植物种植在一起。由后面的词义可推出siblings的意思是同类植物。故选D

2.推断题。从第一自然段Some do, scientists say, according to a report by Science News in early 2010.可知植物也能够分辨出它的同类，第二自然段对这个说法进行了一项有关jewelweeds凤仙花的研究，所以在此是为了点明主题。

3.细节题。由第三段第一句When jewelweeds were planted in pots with strangers, the plants started to grow more leaves than if they had been planted alone.当把凤仙花和不同种类的植物种植在一起时，它就会比单独种植时生长出更多的叶子。故可知，答案选C

4.主旨题。这篇文章讲的是科学家通过实验，发现植物也可以辨别出哪些植物与自己是同一种类的。故选C.

考点：科普类说明文