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。

The technology of freezing stem cells from different strains of chicken can do all the followingEXCEPT that____．

A:farmers can order certain strains of chicken only B:Origen can supply all the strains of chicken the market might need C:chicken farmers order certain strains of chicken for economic reasons D:chicken farmers can be supplied with whatever strain they need

On Antibodies Substances foreign to the body, such as disease-causing bacteria and viruses and other infectious agents, are recognized by the body s immune system as invaders. Our natural defenses against these infectious agents are antibodies, proteins that seek out the antigens (抗原) and help destroy them. Antibodies have two very useful characteristics. First, they are extremely specific; that is, each antibody binds to and attacks one particular antigen. Second, some antibodies, once activated by the occurrence of a disease, continue to confer resistance against that disease. Classic example are the antibodies to the childhood diseases of chickenpox(水痘) and measles. The second characteristic of antibodies makes it possible to develop vaccines. A vaccine (痘苗) is a preparation of killed or weakened bacteria or viruses that, when introduced into the body, stimulates the production of antibodies against the antigens it contains. It is the first trait of antibodies, their specificity, that makes monoclonal antibody technology so valuable. Not only can antibodies be used therapeutically(在治疗上), to protect against disease; they can also help to .diagnose a wide variety of illnesses, and can detect the presence of drugs, viral and bacterial products, and other unusual or abnormal substances in the blood. Given such a diversity of uses for these diseased-fighting substances, their production in pure quantities has long been the focus of scientific investigation. The conventional method was to inject a laboratory animal with an antigen and then, after antibodies had been formed, collect those antibodies from the blood serum(血清) (Antibody containing blood serum is called antiserum (抗血清)). There are two problems with this method: It yields antiserum that contains undesired substances, and it provides a very small amount of usable antibody. Monoclonal antibody technology allows us to produce large amounts of pure antibodies. in the following way: we can obtain cells that produce antibodies naturally; we also have available a class of cells that can grow continually in cell culture (培养). If we form a hybrid (混血儿) that combines the characteristic of "immortality"(永生)with the ability to produce the desired substance, we would have, in effect, a factory to produce antibodies that work around the clock. In monoclonal antibody technology, tumor cells that can replicate (重复) endlessly are fused with mammalian cells that produce an antibody. The result of this cell fusion is a "hybridoma" (杂交瘤), which will continually produce antibodies. These antibodies are called monoclonal because they come from only one type of cell, the hybridoma cell; antibodies produced by conventional methods, on the other hand, are derived from preparations containing many kinds of cells, and hence are called polyclonal. An example of how monoclonal antibodies are derived is described below. A myeloma is a tumor of the bone marrow (骨髓) that can be adapted to grow permanendy in cell culture. When myeloma cells were fused with antibody-producing mammalian spleen cells, it was found that the resulting hybrid cells, or hybridomas, produced large amounts of monoclonal(骨髓瘤) antibody. This product of cell fusion combined the desired qualities of the two different types of cells: the ability to grow continually, and the ability to produce large amounts of pure antibody. Because selected hybrid cells produce only one specific antibody, they are more pure than the polyclonal antibodies produced by conventional techniques. They are potentially more effective than conventional drugs in fighting disease, since drugs attack not only the foreign substance but the body’s own cells as well, sometimes producing undesirable side effects such as nausea(恶心) and allergic reactions. Monoclonal antibodies attack the target molecule and only the target molecule, with no or greatly diminished side effects. Which of the following statements is false?

A:The conventional method produces the polyclonal antibodies. B:The conventional method provides a very small amount of antibody. C:Hybridoma can produce antibodies around the clock. D:Antibody might be an invader to the body’s immune system.

On Antibodies Substances foreign to the body, such as disease-causing bacteria and viruses and other infectious agents, are recognized by the body s immune system as invaders. Our natural defenses against these infectious agents are antibodies, proteins that seek out the antigens (抗原) and help destroy them. Antibodies have two very useful characteristics. First, they are extremely specific; that is, each antibody binds to and attacks one particular antigen. Second, some antibodies, once activated by the occurrence of a disease, continue to confer resistance against that disease. Classic example are the antibodies to the childhood diseases of chickenpox(水痘) and measles. The second characteristic of antibodies makes it possible to develop vaccines. A vaccine (痘苗) is a preparation of killed or weakened bacteria or viruses that, when introduced into the body, stimulates the production of antibodies against the antigens it contains. It is the first trait of antibodies, their specificity, that makes monoclonal antibody technology so valuable. Not only can antibodies be used therapeutically(在治疗上), to protect against disease; they can also help to .diagnose a wide variety of illnesses, and can detect the presence of drugs, viral and bacterial products, and other unusual or abnormal substances in the blood. Given such a diversity of uses for these diseased-fighting substances, their production in pure quantities has long been the focus of scientific investigation. The conventional method was to inject a laboratory animal with an antigen and then, after antibodies had been formed, collect those antibodies from the blood serum(血清) (Antibody containing blood serum is called antiserum (抗血清)). There are two problems with this method: It yields antiserum that contains undesired substances, and it provides a very small amount of usable antibody. Monoclonal antibody technology allows us to produce large amounts of pure antibodies. in the following way: we can obtain cells that produce antibodies naturally; we also have available a class of cells that can grow continually in cell culture (培养). If we form a hybrid (混血儿) that combines the characteristic of "immortality"(永生)with the ability to produce the desired substance, we would have, in effect, a factory to produce antibodies that work around the clock. In monoclonal antibody technology, tumor cells that can replicate (重复) endlessly are fused with mammalian cells that produce an antibody. The result of this cell fusion is a "hybridoma" (杂交瘤), which will continually produce antibodies. These antibodies are called monoclonal because they come from only one type of cell, the hybridoma cell; antibodies produced by conventional methods, on the other hand, are derived from preparations containing many kinds of cells, and hence are called polyclonal. An example of how monoclonal antibodies are derived is described below. A myeloma is a tumor of the bone marrow (骨髓) that can be adapted to grow permanendy in cell culture. When myeloma cells were fused with antibody-producing mammalian spleen cells, it was found that the resulting hybrid cells, or hybridomas, produced large amounts of monoclonal(骨髓瘤) antibody. This product of cell fusion combined the desired qualities of the two different types of cells: the ability to grow continually, and the ability to produce large amounts of pure antibody. Because selected hybrid cells produce only one specific antibody, they are more pure than the polyclonal antibodies produced by conventional techniques. They are potentially more effective than conventional drugs in fighting disease, since drugs attack not only the foreign substance but the body’s own cells as well, sometimes producing undesirable side effects such as nausea(恶心) and allergic reactions. Monoclonal antibodies attack the target molecule and only the target molecule, with no or greatly diminished side effects. Which of the following statements is false?

A:The conventional method produces the polyclonal antibodies. B:The conventional method provides a very small amount of antibody. C:Hybridoma can produce antibodies around the clock. D:Antibody might be an invader to the body’s immune system.

On Antibodies Substances foreign to the body, such as disease-causing bacteria and viruses and other infectious agents, are recognized by the body s immune system as invaders. Our natural defenses against these infectious agents are antibodies, proteins that seek out the antigens (抗原) and help destroy them. Antibodies have two very useful characteristics. First, they are extremely specific; that is, each antibody binds to and attacks one particular antigen. Second, some antibodies, once activated by the occurrence of a disease, continue to confer resistance against that disease. Classic example are the antibodies to the childhood diseases of chickenpox(水痘) and measles. The second characteristic of antibodies makes it possible to develop vaccines. A vaccine (痘苗) is a preparation of killed or weakened bacteria or viruses that, when introduced into the body, stimulates the production of antibodies against the antigens it contains. It is the first trait of antibodies, their specificity, that makes monoclonal antibody technology so valuable. Not only can antibodies be used therapeutically(在治疗上), to protect against disease; they can also help to .diagnose a wide variety of illnesses, and can detect the presence of drugs, viral and bacterial products, and other unusual or abnormal substances in the blood. Given such a diversity of uses for these diseased-fighting substances, their production in pure quantities has long been the focus of scientific investigation. The conventional method was to inject a laboratory animal with an antigen and then, after antibodies had been formed, collect those antibodies from the blood serum(血清) (Antibody containing blood serum is called antiserum (抗血清)). There are two problems with this method: It yields antiserum that contains undesired substances, and it provides a very small amount of usable antibody. Monoclonal antibody technology allows us to produce large amounts of pure antibodies. in the following way: we can obtain cells that produce antibodies naturally; we also have available a class of cells that can grow continually in cell culture (培养). If we form a hybrid (混血儿) that combines the characteristic of "immortality"(永生)with the ability to produce the desired substance, we would have, in effect, a factory to produce antibodies that work around the clock. In monoclonal antibody technology, tumor cells that can replicate (重复) endlessly are fused with mammalian cells that produce an antibody. The result of this cell fusion is a "hybridoma" (杂交瘤), which will continually produce antibodies. These antibodies are called monoclonal because they come from only one type of cell, the hybridoma cell; antibodies produced by conventional methods, on the other hand, are derived from preparations containing many kinds of cells, and hence are called polyclonal. An example of how monoclonal antibodies are derived is described below. A myeloma is a tumor of the bone marrow (骨髓) that can be adapted to grow permanendy in cell culture. When myeloma cells were fused with antibody-producing mammalian spleen cells, it was found that the resulting hybrid cells, or hybridomas, produced large amounts of monoclonal(骨髓瘤) antibody. This product of cell fusion combined the desired qualities of the two different types of cells: the ability to grow continually, and the ability to produce large amounts of pure antibody. Because selected hybrid cells produce only one specific antibody, they are more pure than the polyclonal antibodies produced by conventional techniques. They are potentially more effective than conventional drugs in fighting disease, since drugs attack not only the foreign substance but the body’s own cells as well, sometimes producing undesirable side effects such as nausea(恶心) and allergic reactions. Monoclonal antibodies attack the target molecule and only the target molecule, with no or greatly diminished side effects. Which of the following statements is false?

A:The conventional method produces the polyclonal antibodies. B:The conventional method provides a very small amount of antibody. C:Hybridoma can produce antibodies around the clock. D:Antibody might be an invader to the body’s immune system.

On Antibodies Substances foreign to the body, such as disease-causing bacteria and viruses and other infectious agents, are recognized by the body s immune system as invaders. Our natural defenses against these infectious agents are antibodies, proteins that seek out the antigens (抗原) and help destroy them. Antibodies have two very useful characteristics. First, they are extremely specific; that is, each antibody binds to and attacks one particular antigen. Second, some antibodies, once activated by the occurrence of a disease, continue to confer resistance against that disease. Classic example are the antibodies to the childhood diseases of chickenpox(水痘) and measles. The second characteristic of antibodies makes it possible to develop vaccines. A vaccine (痘苗) is a preparation of killed or weakened bacteria or viruses that, when introduced into the body, stimulates the production of antibodies against the antigens it contains. It is the first trait of antibodies, their specificity, that makes monoclonal antibody technology so valuable. Not only can antibodies be used therapeutically(在治疗上), to protect against disease; they can also help to .diagnose a wide variety of illnesses, and can detect the presence of drugs, viral and bacterial products, and other unusual or abnormal substances in the blood. Given such a diversity of uses for these diseased-fighting substances, their production in pure quantities has long been the focus of scientific investigation. The conventional method was to inject a laboratory animal with an antigen and then, after antibodies had been formed, collect those antibodies from the blood serum(血清) (Antibody containing blood serum is called antiserum (抗血清)). There are two problems with this method: It yields antiserum that contains undesired substances, and it provides a very small amount of usable antibody. Monoclonal antibody technology allows us to produce large amounts of pure antibodies. in the following way: we can obtain cells that produce antibodies naturally; we also have available a class of cells that can grow continually in cell culture (培养). If we form a hybrid (混血儿) that combines the characteristic of "immortality"(永生)with the ability to produce the desired substance, we would have, in effect, a factory to produce antibodies that work around the clock. In monoclonal antibody technology, tumor cells that can replicate (重复) endlessly are fused with mammalian cells that produce an antibody. The result of this cell fusion is a "hybridoma" (杂交瘤), which will continually produce antibodies. These antibodies are called monoclonal because they come from only one type of cell, the hybridoma cell; antibodies produced by conventional methods, on the other hand, are derived from preparations containing many kinds of cells, and hence are called polyclonal. An example of how monoclonal antibodies are derived is described below. A myeloma is a tumor of the bone marrow (骨髓) that can be adapted to grow permanendy in cell culture. When myeloma cells were fused with antibody-producing mammalian spleen cells, it was found that the resulting hybrid cells, or hybridomas, produced large amounts of monoclonal(骨髓瘤) antibody. This product of cell fusion combined the desired qualities of the two different types of cells: the ability to grow continually, and the ability to produce large amounts of pure antibody. Because selected hybrid cells produce only one specific antibody, they are more pure than the polyclonal antibodies produced by conventional techniques. They are potentially more effective than conventional drugs in fighting disease, since drugs attack not only the foreign substance but the body’s own cells as well, sometimes producing undesirable side effects such as nausea(恶心) and allergic reactions. Monoclonal antibodies attack the target molecule and only the target molecule, with no or greatly diminished side effects. Which of the following statements is false?

A:The conventional method produces the polyclonal antibodies. B:The conventional method provides a very small amount of antibody. C:Hybridoma can produce antibodies around the clock. D:Antibody might be an invader to the body’s immune system.