It is easy for us to tell who our family members are, but do plants recognize(識(shí)別) 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(反應(yīng))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
1.D
2.B
3.C
4.C
【解析】
試題分析:這篇文章講的是科學(xué)家通過做實(shí)驗(yàn),發(fā)現(xiàn)將一種植物與不同種類的植物種植在一起,它會(huì)和其他植物競(jìng)爭(zhēng)養(yǎng)分,將會(huì)長(zhǎng)的更好,如果單獨(dú)種植的話,則會(huì)分享資源,而不競(jìng)爭(zhēng)。
1.推斷題。由第二段最后一句In their experiments, Murphy and Dudley planted jewelweeds in pots with either siblings or strangers.在他們的實(shí)驗(yàn)中,Murphy and Dudley將鳳仙花要么和同類植物種植在一起,要么和不同的植物種植在一起。由后面的詞義可推出siblings的意思是同類植物。故選D
2.推斷題。從第一自然段Some do, scientists say, according to a report by Science News in early 2010.可知植物也能夠分辨出它的同類,第二自然段對(duì)這個(gè)說(shuō)法進(jìn)行了一項(xiàng)有關(guān)jewelweeds鳳仙花的研究,所以在此是為了點(diǎn)明主題。
3.細(xì)節(jié)題。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.當(dāng)把鳳仙花和不同種類的植物種植在一起時(shí),它就會(huì)比單獨(dú)種植時(shí)生長(zhǎng)出更多的葉子。故可知,答案選C
4.主旨題。這篇文章講的是科學(xué)家通過實(shí)驗(yàn),發(fā)現(xiàn)植物也可以辨別出哪些植物與自己是同一種類的。故選C.
考點(diǎn):科普類說(shuō)明文
點(diǎn)評(píng):本文較難,科技類的文體是比較繁瑣的,因?yàn)閷S忻~較多。學(xué)生在解答這類題目時(shí),首先對(duì)文章有大致的掌握,對(duì)于文章一遍沒有看懂時(shí),可以先看題目,按照文章題目的提示,再在文章中找出相對(duì)應(yīng)的地方,然后仔細(xì)分析文章的上下文,同時(shí)對(duì)于專有名詞可以用筆畫出,通過多個(gè)地方的比較就可以猜出意思了。
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