Question

    Don’t like seeds in your tomatoes? You might be pleased to know that seedless ones have been created by gene editing.

This could create a wide range of seedless fruits, but few may ever be seen in the supermarket if regulators decide to treat gene-edited crops in the same way as genetically engineered ones.

Several seedless fruits, from bananas to grapes, are already available, but have mostly come about by luck rather than design. And although there are a few seedless varieties of tomatoes, they’ve taken researchers many years to create.

Now it can be done very quickly, as Keishi Osakabe at Tokushima University in Japan has shown. His team used the CRISPR gene editing technology to make fruits develop even though no seeds had begun to form. “We haven’t tasted them yet, but in theory they should taste the same,” says Osakabe.

There have been a few efforts to create seedless tomatoes using earlier genetic-engineering techniques. These methods take longer time compared with CRISPR.

Some “seedless” fruits just have very small seeds, and still require pollination (授粉). But completely seedless fruits like the edited tomato do not require pollination at all. Such plants could improve food security by reducing our reliance on smaller bee populations, says Saul Cunningham at the Australian National University. Many fruit growers buy bees to pollinate their crops.

There is a deficiency for farmers, however. Seedless plants usually have to be grown from cuttings, which involves more labor than planting seeds.

CRISPR could be used to develop other types of fruit that don’t require pollinator, as well as introduce beneficial mutations (突变), says Osakabe.

But to make it on to the supermarket, gene-edited plants may have to meet the same standards as genetically engineered plants, which would greatly increase costs. Some argue chat since gene editing is used to introduce mutations already found in some of the plants we eat, it should not require such strict regulations.

1.What has been the problem with tomatoes created in the past?

A.Their taste was not very good. B.They still had a few big seeds.

C.Their genes could not be recognized. D.They took quite a long time to create.

2.What did Keishi Osakabe’s team do?

A.They edited tomatoes’ genes.

B.They changed the taste of tomatoes.

C.They made seedless bananas and grapes.

D.They created genetically engineered tomatoes.

3.Why is CRISPR better than previous methods?

A.It will still require pollination.

B.It will remain unaffected without bees.

C.It will reduce people’s reliance on food security.

D.It will make many growers buy bees for pollination.

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

A.Danger. B.Disadvantage.

C.Benefit. D.Solution.

Answer

1.D

2.A

3.B

4.B

【解析】

本文是说明文。文章介绍了研究人员通过基因技术培育出无籽西红柿。

1.细节理解题。由第三段中的 And although there are a few seedless varieties of tomatoes, they’ve taken researchers many years to create.（虽然有一些无籽品种的西红柿，但研究人员花了很多年才创造出来）可知，之前的无籽西红柿生长培育周期相当的长。故选D项。

2.推理判断题。由第四段中的 His team used the CRISPR gene-editing technology to make fruits develop even though no seeds had begun to form.（他的团队使用了CRISPR基因编辑技术，使水果得以生长，尽管还没有种子开始形成）可知， Keish Osakabe的科研队伍为了获得无籽西红柿而编辑了西红柿的基因。故选A项。

3.细节理解题。由第六段中的 But completely seedless fruits like the edited tomato do not require pollination at all.（但是像编辑过的番茄这样完全无籽的水果根本不需要授粉）可知，无籽西红柿不需要授粉，所以即使没有蜜蜂，这项技术也不会受到影响。故选B项。

4.词义猜测题。划线单词所在句有转折副词“however”存在，因此可推知后文讲述的是无籽西红柿给农民带来的不利之处。且后文“Seedless plants usually have to be grown from cuttings, which involves more labor than planting seeds.（无籽植物通常要从插枝开始生长，这比播种要耗费更多的劳力）可知，无籽植物需要投入更多的劳动力，所以对农民而言是不利的，故deficiency在此处的意思和disadvantage 一致。故选B项。