问题 解答题

阅读下列材料,回答有关问题:

材料一 俗话说得好:“种瓜得瓜,种豆得豆.”“龙生龙,凤生凤,老鼠生儿会挖洞.”

材料二 新疆吐鲁番的葡萄以粒大、甜度高、产量高而著称.有人将其引入攀枝花种植,其果实的品质和产量大大降低.

材料三 科学工作者将一种红果皮圆形果与另一种绿果皮扁形果的苹果作亲本进行杂交.后代中出现了红果皮扁形果和绿果皮圆形果两种与亲本不同的新类型.

(1)材料一所描述的现象叫做______.材料二及材料三所描述的现象叫做______.

(2)吐鲁番葡萄在攀枝花种植品质降低的变异与红果皮扁形果和绿果皮圆形果的变异相比较,前者是______的变异,后者是______的变异.引起这种差异的根本原因是后者涉及到______的改变.

(3)材料三中涉及到两对相对性状,它们分别是______、______.

答案

(1)遗传是指亲子间的相似性,变异是指子代与亲代之间的差异,以及子代个体之间的差异的现象.“种豆得豆,种瓜得瓜”“龙生龙,凤生凤,老鼠生儿会挖洞.”体现了亲代与子代之间具有相同的性状,因此体现了生物的遗传现象.

(2)哈密瓜在攀枝花种植甜度降低的变异,是环境改变引起,遗传物质没有发生改变,属于不可遗传的变异.而红果皮扁形果和绿果皮圆形果的变异相比,是遗传物质改变引起的变异,属于可遗传的变异.

(3)同种生物同一性状的不同表现形式称为相对性状.材料三中涉及到的两对相对性状,它们分别是红果皮与绿果皮,圆形果与扁形果.

故答案为:(1)遗传;变异(2)不可遗传;可遗传;遗传物质(3)红果皮与绿果皮;圆形果与扁形果

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     It has been more than twenty years since pioneering British computer programmer, Sir Tim Berners

Lee, created the World Wide Web. But could he have ever imagined how much the web would change

our lives? And would he approve of how some British students are taking advantage of his invention?

     Universities and exam boards around the UK are becoming increasingly concerned with the rising

number of cases of plagiarism, many of which are facilitated (助长) by the Internet access.

     In the UK most school and university students complete coursework throughout the academic year

which contributes toward their final mark. In many cases coursework makes up the main part of the

qualification. Since coursework is completed in the students' own time it cannot be monitored by teachers

in the same way as an exam.

     Derec Stockley, director of examinations in the UK, explains, "Plagiarism affects coursework more

than anything else, and in the cases that come to our attention, more and more are linked to the Internet."

     At a university level recent reports suggest that plagiarism has evolved from separate cases of

individual cheating to systematic and even commercial operation. Students can now pay for bespoke

essays to be written for them by experts.

      It is estimated that the market in online plagiarism is now worth 200 million pounds a year. Every

month more and more websites offering to write student's essays for them appear on the Internet.

Barclay Littlewood, owner of Degree Essays UK employs 3,500 specialist writers and charges between

120 pounds and 4,000 pounds per essay. However, Mr. Littlewood refutes the accusation that he is

helping students to cheat.

1. What dose the underlined word "plagiarism" in Paragraph 2 mean in the passage?

A. Coursework.     

B. Problems of the Internet.

C. Learning pressure.  

D. Cheating.

2. Which of the following statements is mentioned by the author?

A. With the help of online plagiarism, students can write more creative coursework.

B. There will be no problem if online plagiarism is a systematic and commercial operation.

C. The Internet seems to have contributed much to the problem of online plagiarism.

D. Teachers should lay more emphasis on exams than coursework.

3. It can be inferred from the text that the author seems to ________.

A. blame Sir Tim Berners Lee for having created the World Wide Web

B. worry about the quality of students' coursework influenced by the World Wide Web

C. be in favour of Littlewood's defense against the accusation of him

D. have studied the problem of online plagiarism for nearly 20 years

4. Who should be blamed for online plagiarism?

A. Barclay Littlewood.

B. Sir Tim Berners Lee.

C. Derec Stockley.

D. Nobody.

5. The paragraph following the passage will most probably be about ________.

A. the author's opinions of Mr. Littlewood

B. different people's opinions on plagiarism

C. how students use the website of Mr. Littlewood

D. Mr. Littlewood's defence against those who accused him of his website