问题 问答题 简答题

解释下列遗传学名词。

答案

参考答案:

(1)遗传:遗传信息从亲本和祖先传递给后裔。血型的信息能通过遗传而代代相传。

(2)染色体:染色体系和遗传密切相关的细胞器。染色体位于细胞核内。人类体细胞有23对染色体,其中22对为常染色体,一对为性染色体。每条染色体含2条染色单体,借着丝点将其分为长臂(q)和短臂(p)。染色体由核酸(主要是DNA)和蛋白质组成。

(3)基因:基因是一段具有编码能力的DNA,即在DNA(或RNA)分子上代表一个遗传功能单位的核苷酸特定序列。它是在染色体上占有一定位置的遗传单位。

(4)等位基位:在一特定座位上的基因所采取的各种形式,被称为等位基因。由两个以上个别等位基因组成的一组等位基因为"复等位基因"。

(5)基因定位:对同一染色体上两基因之间的距离或它们的连锁程度的测定。

(6)多态性:在一个繁育群体中,保持两种或两种以上类型的个体。

(7)基因型:一个个体所带基因的总和称为基因型,基因型可通过家系调查推测。

(8)表型:可以直接检测出的基因产物称为表型。

(9)性状:性状是指一种可检测的、由遗传决定的特性。性状能按预期的方式从上一代传给下一代。血型是血液特定的遗传性状。

阅读理解

From the first use of the rocket to carry satellites into space to the setting up of space stations, human beings have been putting great effort into space research. And so far, we have achieved many successes. But there are still numerous tasks in front of us and we should not stop trying to progress.

The international space station (ISS) is an important step we should take in space exploration. It is not only helpful but also essential. It provides a proper space environment for many experiments that we have wanted to do for a long time. It is also a base for the observations of the earth and the universe. It could also be an important base for later travel to the moon and Mars. In a word, if we want to explore space more, the first thing we should do is to set up a space station.

As the space station costs a lot of money, it is hard for one country alone to establish one. The USA seems to be the only country that has the ability to build a space station alone,and it has tried to do so, but not very successful. So it aggregated many other countries to work on it together. Though it is still extremely expensive, it is much cheaper than doing it alone. It is really a job that needs everyone’s effort and will benefit everyone.

Led by the U.S. and Russia, the ISS is a joint project between six space agencies involving 16 countries. Called the greatest achievement in human cooperation, the ISS has come to the end of a ten-year’s hard work in construction. China has applied for participation in (taking part in) the project many times. Unfortunately all the applications were rejected, which drove China onto the path of independent development. As the Long March Ⅱ-F/T1 carrier rocket blasted off (leave the ground) and successfully carried the Tiangong-1 into space on September 29, 2011, China takes a big step toward its Space Station Era.

Some West media suggested that the successful launch of Tiangong-1 would disturb the balance of global space power, raising concerns (关注) about “China threat”. China’s space project is not designed for military (军事的) purpose but for developing space technology to explore space resources and make use of them for mankind’s well-being.

小题1:From Paragraph 2 we learn that ________.

A.the necessity of building the international space station is not realized now

B.many experiments have been done in the international space station

C.the international space station is necessary for people to explore space more

D.people have traveled to Mars from the international space station小题2:Which of the following is NOT a reason for countries’ cooperation in building the international space station?

A.That it requires a lot of money.

B.That it needs everyone’s effort.

C.That it will benefit every participating country.

D.That it is too far away from the earth.小题3:The underlined word “aggregated” in Paragraph 3 can be replaced by “________”.

A.united

B.scolded

C.allowed

D.forbade小题4:China wants to build its space station in order to __________.

A.break the balance of global space power

B.show that China can build space station alone

C.raise international concerns about “China threat”

D.make use of space peacefully for mankind’s well-being

单项选择题