果蝇的一条染色体上正常基因的排列顺序为abc·defghi，中间的“·”代表着丝

发布时间：2017-05-08 21:01 │ 来源：www.tikuol.com

题型：选择题

问题：

果蝇的一条染色体上正常基因的排列顺序为abc·defghi，中间的“·”代表着丝点。下表表示由正常染色体发生变异后基因顺序变化的四种情况，有关叙述错误的是

[ ]

A．2是染色体某一片段缺失引起的

B．3是染色体着丝点改变引起的

C．4是染色体增加了某一片段引起的

D．1是染色体某一片段位置颠倒引起的

考点：染色体变异

题型：选择题

阅读理解。

       News 1: A gas explosion (瓦斯爆炸) happened on October 20 in a coal mine (煤矿) in Daping, Henan.
It has killed 129 people so far. Another 19 are still missing. More than 400 workers were at the mine at the
time. Only 298 ran out.
       News 2: Scientists have found some caves (洞穴) in the north part of the Mogao Grottoes (莫高窟)
of Dunhuang in Gansu. Now the north part has 248 caves in all. Altogether there are 735 Dunhuang Mogao
Grottoes. People began to make Mogao Grottoes from 366 AD. Pictures in the caves show what people's
lives were like in the past.
       New 3: Are girls cleverer than boys? Maybe. In a new study, scientists found that female chimps used
sticks two years earlier than male chimps in Africa. Female chimps watched their mums look for food. The
males climbed trees. The same thing also happens in the world of people. Girls learn to write and draw before
boys, while boys learn to play with balls before girls.

1. Which of the above news stories talks about an accident?

A. News 1
B. News 2
C. News 3
D. All of them

2. We can tell from the Mogao Grottoes pictures _______.

A. there are many caves in China
B. how to live a happy life
C. how people lived long ago
D. caves should be protected

3. The reporter of News 3 is _______ that girls are cleverer than boys.

A. very sure
B. doubtful (怀疑的)
C. sure
D. not sure

4. Which of the following statements is true?

A. More than 400 workers lived through the mine explosion.
B. Female chimps don't like to learn things from their mums.
C. Boys learn to play with balls earlier than girls.
D. All caves in China have pictures on the walls.

5. "Chimp" in the last news story probably is _______.

A. a kind of food
B. a kind of animal
C. the name of a man
D. the name of a game

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《锅炉大气污染物排放标准》规定，燃气锅炉烟囱高度最低不得低于？

A.8m

B.15m

C.12m

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连续驱动摩擦焊的加热过程分为（）。

A.初始摩擦

B.不稳定摩擦

C.稳定摩擦

D.停车阶段

E.连续摩擦

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保守稳健型投资者一般购买国债、企业债券等证券。( )

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