Task2. Open the brackets and use the verb in the appropriate voice and tense-aspect form.

1. If an extremely virulent forms of viruses (to release) from the laboratory, it (to cause) worldwide epidemics.

2. Some ethical dilemmas (to associate) with the production of transgenic organisms.

3. Certain restrictions (to impose) on those people working with pathogenic microorganisms.

4. Hemophiliacs are people who (to be) at risk of bleeding to death after suffering minor cuts or bruises.

5. In its natural state, copper (to find) combined with other elements in the mineral chalcopyrite.

6. Human insulin (to produce) using recombinant bacteria since 1978.

7. In 1973 scientists firstly (to remove) a specific gene from one bacterium and (to insert) it into another.

8. The application of bacteria (to investigate) in different fields.

Task3. Insert either the definite article or the zero article. Explain their use.

1. … corn (maize) was one of … first food crops cultivated by … human beings.

2. There are … fears that recombinant DNA experiments with … pathogenic microorganisms may result in … formation of extremely virulent forms.

3. … discovery that bacteria fix … nitrogen in … root nodules of leguminous plants was of great importance.

4. … field of medicine employs some of … most dramatic applications in … biotechnology.

5. … hybridization and … selective breeding was used to increase … food production and … quality of wheat and rice crops.

Task4. Write one sentence beginning with if instead of these two.

1. There are a lot of fears connected with unregulated genetic engineering procedures. The National Institutes of Health created a body of rules governing the handling of microorganisms in recombinant DNA experiments.

2. Many bacteria are being intensively investigated. In recent years, bacteriology has been greatly expanded from its concentration on bacterial disease.

3. Factor VIII, a blood-clotting protein is not produced, or has greatly reduced activity, in people who have hemophilia. Hemophiliacs are at risk of bleeding to death after suffering minor cut.

Task5. These are answers. Make up questions.

1. In response to fears of disastrous consequences of unregulated genetic engineering procedures.

2. Diverse strains of plants or animals.

3. They helped to understand many aspects of DNA replication and the expression of genetic material.

4. Basic biotechnology techniques and their laboratory’s success in producing rat insulin with genetically engineered bacteria.

5. When American biochemist James Watson and British biophysicist Francis Crick presented their double-helix model of DNA.

6. They are called restriction enzymes.

Task6. Render the following text into English.

Успехи микробиологии во второй половине XIX века привели к обнаружению чрезвычайного разнообразия типов жизни в микромире. Следующий вопрос, заинтересовавший исследователей, был: как объяснить такое многообразие, определить его границы, выявить, на чём оно основано? Постановкой этой проблемы, имеющей общебиологическое значение, мы обязаны двум крупнейшим микробиологам прошлого века А. Клюйверу и К. Ван Нилю ( A.Kluyver, C. van Niel). Эти учёные провели сравнительные биохимические исследования в относительно далеко отстоящих друг от друга физиологических группах микроорганизмов. Было изучено много форм микроорганизмов и примерно к середине XX века сформулировано то, что теперь называют теорией биохимического единства жизни.

В чём же конкретно состоит биохимическое единство жизни? Общее основано на единстве конструктивных, энергетических процессов и механизмов передачи генетической информации. Все живые организмы построены из однотипных химических макромолекул, универсальной единицей биологической энергии служит АТФ, в основе физиологического разнообразия живых существ лежит несколько метаболических путей.

ADDITIONAL TEXT

Task1. Read the text about bacteria which are able to manufacture nonbacterial proteins due to introduced nonbacterial genes. Among the proteins made by recombinant-DNA methods are insulin and interferon.

Useful Proteins from Recombinant Bacteria

By Walter Gilbert and Lydia Villa-Komaroff

A living cell is a protein factory. It synthesizes the enzymes and other proteins that maintain its own integrity and physiological processes, and (in multicelled organisms) it often synthesizes and secretes other proteins that perform some specialized function contributing to the life of the organism as a whole. Different kinds of cells make different proteins, following instructions encoded in the DNA of their genes. Recent advances in molecular biology make it possible to alter those instructions in bacterial cells, thereby designing bacteria that can synthesize nonbacterial proteins. The bacteria are "recombinants." They contain, along with their own genes, part or all of a gene from a human cell or other animal cell. If the inserted gene is one for a protein with an important biomedical application, a culture of the recombinant bacteria, which can be grown easily and at low cost, will serve as an efficient factory for producing that protein.

Many laboratories in universities and in an emerging "applied genetics" industry are working to design bacteria able to synthesize such nonbacterial proteins. A growing tool kit of "genetic engineering" techniques makes it possible to isolate one of the million-odd genes of an animal cell, to fuse that gene with part of a bacterial gene and to insert the combination into bacteria. As those bacteria

multiply they make millions of copies of their own genes and of the animal gene inserted among them. If the animal gene is fused to a bacterial gene in such a way that a bacterium can treat the gene as one of its own, the bacteria will produce the protein specified by the animal gene. New ways of rapidly and easily determining the exact sequence of the chemical groups that constitute a molecule of DNA make it possible to learn the detailed structure of such "cloned" genes. After the structure is known it can be manipulated to produce DNA structures that function more efficiently in the bacterial cell.

In this article we shall first describe some of these techniques in a general way and then tell how we and our colleagues Argiris Efstratiadis, Stephanie Broome, Peter Lomedico and Richard Tizard applied them in our laboratory at Harvard University to copy a rat gene that specifies the hormone insulin, to insert the gene into bacteria and to get the bacteria to manufacture a precursor of insulin. In an exciting application of this technology Charles Weissmann and his colleagues at the University of Zurich recently constructed bacteria that produce human interferon, a potentially useful antiviral protein.