单选题

Clone Farm

Factory farming could soon enter a new era of mass production. Companies in the US are developing the technology needed to “clone” chickens on a massive scale1. Once a chicken with desirable traits has been bred or genetically engineered2, tens of thousands of eggs, which will hatch into identical copies3, could roll off the production lines every hour. Billions of clones could be produced each year to supply chicken farms with birds that all grow at the same rate, have the same amount of meat and taste the same.

This, at least, is the vision of the US’s National Institute of Science and Technology, which has given Origen Therapeutics of Burlingame, California, and Emhrex of North Carolina $4.7 million to help fund research4. The prospect has alarmed animal welfare groups, who fear it could increase the suffering of farm birds.

That’s unlikely to put off5 the poultry industry, however , which wants disease-resistant birds that grow faster on less food. “Producers would like the same meat quanrity but to use reduced inputs to get there,” says Mike Fitzgerald of Origen. To meet this demand, Origen aims to “create an animal that is effectively a clone”, he says. Normal cloning doesn’t work in birds because eggs can’t be removed and implanted. Instead, the company is trying to bulk-grow6 embryonic stem cells7 taken from fertilized eggs as soon as they’re laid. “The trick is to culture8 the cells without them starting to distinguish, so they remain pluripotent,” says Fitzgerald.

Using a long-established technique, these donor cells will then be injected into the embryo of a freshly laid, fertilized recipient egg9, forming a chick that is a “chimera”. Strictly speaking a chimera isn’t a clone, because it contains cells from both donor and recipient. But Fitzgcrald says it will be enough if, say, 95 percent of a chicken’s body develops from donor cells. “In the poultry world, it doesn’t matter if it’s not 100 percent,” he says.

Another challenge for Origen is to scale up10 production. To do this, it has teamed up with11 Embrex, which produces machines that can inject vaccines into up to 50,000 eggs12 an hour. Embrex is nowtrying to modify the machines to locate the embryo and inject the cells into precisely the right spot without killing it.

In future, Origen imagines freezing stem cells from different strains of chicken13. If orders come in for a particular strain , millions of eggs could bc produced in months or even weeks. At present, maintaining all the varieties the market might call for is too expensive for breeders, and it takes years to bread enough chickens to produce the billions of eggs that farmers need.

 

词汇: 

clone / kləʊn/ n.克隆，无性繁殖

implant / ɪmˈplɑ:nt / vt. 植入；移植
embryonic / ˌembriˈɒnɪk / adj. 胚胎的 

fertilise / "fɜ:tɪlaɪz / vt. 使受精

pluripotent / plʊə"rɪpətənt / adj. 多能的 

embryo / ˈembriəʊ/ n. 胚胎
chimera / kaɪˈmɪərə/ n.  嵌合体 

vaccine / "væksi:n/ n.疫苗

 

注释:

1. on a massive scale:大规模

2. genetically engineered:经过基因改造。 genetical engineering:遗传工程

3. hatch into identical copies:孵出如出一辙的 (小)鸡

4. to help fund research:资助研究。 fund用作动词， research是它的宾语。

5. put off:意为“discourage”(使…气馁)。

6. bulk-grow:大量繁殖

7. stem cells:干细胞

8. culture:动词，意思是“培育”。

9. a freshly laid, fertilized recipient egg:新产下的、己受精的、要接受细胞植入的鸡蛋

10. scale up:提高，按比例增加

11. team up with:与……合作

12. up to 50,000 eggs:多达 5万只鸡蛋

13. different strains of chicken:不同品种的鸡

In the third paragraph, by saying “Producers would like the same meat quantity but to use reduced inputs to get there.” Mike Fitzgerald means that he wishes

A:chickens’ quality could be maintained but with less investment. B:chickens" taste could be improved but at less costs. C:chickens" growth rate could be quickened but with less inputs. D:chickens could grow to the same weight but with less feed.

Clone Farm

    Factory farming could soon enter a new era of mass production. Companies in the USare developing the technology needed to "clone" chickens on a massive scale1. Once a chicken with desirable traits has been bred or genetically engineered2, tens of thousands of eggs, which will hatch into identical copies3 , could roll off the production lines every hour. Billions of clones could be produced each year to supply chicken farms with birds that all grow at the same rate, have the same amount of meat and taste the same.

    This, at least, is the vision of theUS"s National Institute of Science and Technology, which has given Origen Therapeutics of Burlingame, California, and Embrex of North Carolina $4.7 million to help fund research4. The prospect has alarmed animal welfare groups, who fear it could increase the suffering of farm birds.

    That"s unlikely to put off5 the poultry industry, however, which wants disease-resistant birds that grow faster on less food. "Producers would like the same meat quantity but to use reduced inputs to get there," says Mike Fitzgerald of Origen. To meet this demand, Origen aims to "create an animal that is effectively a clone", he says. Normal cloning doesn"t work in birds because eggs can"t be removed and implanted. Instead, the company is trying to bulk-grow6, embryonic stem cells7 taken from fertilized eggs as soon as they"re laid. "The trick is to culture8 the cells without them starting to distinguish, so they remain pluripotent," says Fitzgerald.

    Using a long-established technique, these donor cells will then be injected into the embryo of a freshly laid, fertilized recipient egg9, forming a chick that is a "chimera". Strictly speaking a chimera isn"t a clone, because it contains cells from both donor and recipient. But Fitzgerald says it will be enough if, say, 95 percent of a chicken"s body develops from donor cells. "In the poultry world, it doesn"t matter if it"s not 100 percent," he says.

    Another challenge for Origen is to scale up10 production. To do this, it has teamed up with11 Embrex, which produces machines that can inject vaccines into up to 50,000 eggs12 an hour. Embrex is now trying to modify the machines to locate the embryo and inject the cells into precisely the right spot without killing it.

    In future, Origen imagines freezing stem cells from different strains of chicken13. If orders come in for a particular strain, millions of eggs could be produced in months or even weeks. At present, maintaining all the varieties the market might call for is too expensive for breeders, and k takes years to breed enough chickens to produce the billions of eggs that farmers need.


词汇:

Clone/ kləʊn /n. & v.克隆，无性繁殖

embryo / ˈembriəʊ /n.胚胎

implant / "ɪmplɑ:nt /v.植入；移植

chimera / kaɪˈmɪərə /n.嵌合体

embryonic / ˌembriˈɒnɪk /adj.胚胎的

fertilise / "fɜ:tɪlaɪz /v.使受精

pluripotent / plʊə"rɪpətənt /adj.多能的

vaccine / "væksi:n /n.疫苗


注释：

1. on a massive scale:大规模
2. genetically engineered：经过基因改造。genetical engineering：遗传工程
3. hatch into identical copies：孵出如出一辙的（小）鸡
4. help fund research： 资助研究。fund用作动词，research是它的宾语。
5. put off：意为 “discourage”（使……气馁）。
6. bulk-grow： 大量繁殖
7. stem cell：干细胞
8. culture：动词，意思是：培育。
9. a freshly laid, fertilized recipient egg:新产下的；已受精的；要接受细胞植入的鸡蛋
10. scale up： 提高，按比例增加。
11. team up with：与 合作。
12. up to 50,000 eggs：多达 5 万只鸡蛋。
13. different strains of chicken：不同品种的鸡。

In the third paragraph,by saying "Producers would like the same meat quantity but to usereduced inputs to get there".  Mike Fitzgerald means that he wishes____

A:chickens" quality could be maintained but with less investment B:chickens" taste could be improved but at less costs C:chickens" growth rate could be quickened but with less inputs D:chickens could grow to the same weight but with less feed

What is the same meaning of location value? （）

A:Different value B:Different value of same goods at the different place C:Different goods D:Different value of different goods at the same place

Quality and grade are not the same. A fundamental distinction is that ______ .

A:grade is a category assigned to products or services having the same functional us but different technical characteristics B:low quality may not be a problem; low grade is always a problem C:determining and delivering the required levels of quality are not included in the responsibilities of the project manager and the project team D:determining and delivering the required levels of grade are not included in the responsibilities of die project manager and the project team

Your nerve system reacts (to) (what) you imagine to be true (on much the same way) that it (does) to real experiences.

A:to B:what C:on much the same way D:does

Life in the Universe

Many scientists today are convinced that life exists elsewhere in the universe-life probably much like that on our own planet. They reason in the following way.
As far as astronomers can determine, the entire universe is built of the same matter. They have no reason to doubt that matter obeys the same laws in every part of the universe. Therefore, it is reasonable to guess that other stars, with their own planets, were born in the same way as our own solar system. What we know of life on earth suggests that life will arise wherever the proper conditions exist.
Life requires the right amount and kind of atmosphere. This eliminates all those planets in the universe that are not about the same size and weight as the earth. A smaller planet would lose its atmosphere; a larger one would hold too much of it.
Life also requires a steady supply of heat and light. This eliminates double stars, or stars that flare up suddenly. Only single stars that are steady sources of heat and light like our sun would qualify.
Finally, life could evolve only if the planet is just the right distance from its sun. With a weaker sun than our own, the planet would have to be closer to it. With a stronger sun, it would have to be farther away.
If we suppose that every star in the universe has a family of planets, then how many planets might support life First, eliminate those stars that are not like our sun. Next eliminate most of their planets; they are either too far from or too close to their suns. Then eliminate all those planets which are not the same size and weight as the earth. Finally, remember that the proper conditions do not necessarily mean that life actually does exist on a planet. It may not have begun yet, or it may have already died out.
This process of elimination seems to leave very few planets on which earthlike life might be found. However, even if life could exist on only one planet in a million, there are so many billions of planets that this would still leave a vast number on which life could exist.
Astronomers believe that matter in different parts of the universe ______.

A:has different laws B:has one common law C:shares the same laws D:shares no common law

Astronomers believe that matter in different parts of the universe（　）

A:obeys different laws. B:obeys one common law. C:obeys the same laws. D:obeys no common law.

微信扫码获取答案解析
下载APP查看答案解析

您可能感兴趣的题目