III. MICROBIOLOGY

1. The experiment would be ready by the end of the month if they supplied us with all the necessary material on the problem. 2. If a transverse section is made through the cerebral hemispheres, the inner white matter and the embedded grey matter may be observed. 3. All sensations such as touch, pain and temperature are lost if cerebral hemispheres are destroyed.

4. If a piece of ice were placed against the skin, it would cause a sudden change in environment of the body and the sensation of cold would result.

5. If a man touches hot water, he quickly withdraws his hand.

Упражнение 2. Напишите данные предложения так, чтобы они выражали маловероятное предположение.

Образец: If they get all the necessary material, they will be able to go on with their experiment.

If they got all the necessary material, they would be able to go on with their experiment.

1. If an object passes in front of the eyes, the changes in the intensity of the light stimulate the nerve endings in the eye. 2. If food is taken into the mouth, stimulation of the various receptors in the mucous membrane brings about reflex secretions. 3. If one can make a nerve connection between the sensitive receptor cells of the ear and the area in the brain associated with sight, it will be possible to perceive, or «see» sounds.

Упражнение 3. Напишите данные предложения так, чтобы они выражали упущенную возможность совершить действие.

Образец: If the doctor knows the reason of the patient's trouble, he will help him immediately.

If the doctor had known the reason of the patient's trouble yesterday he would have helped him immediately.

1. If the cerebral cortex in this animal is completely removed, no connection reflexes will be formed at all. 2. If she takes part in the conference, she will make a good report. 3. If we use new apparatus, we shall save much time. 4. If the surgeon on duty does not operate patient N., serious complications may result.

Упражнение 4. Переведите следующие предложения c глаголами shall, will, should, would.

1. If you ascend in the atmosphere as in flying an airplane, climbing a high mountain, or riding a fast elevator, the atmospheric pressure, and that in the outer ear, will drop, while that in the middle ear remains the same. 2. Damage to one side of the brain will cause paralysis on the opposite side of the body. 3. He said he would prepare the report on the functions of sense organs. 4. They shall attend this lecture by all means. 5. There are certain aspects in the differential diagnosis which should be considered whenever headache is found to be a distressing complaint in a patient. 6. He would work in the Anatomi- cal Museum if he were free.

Упражнение 5. Прочтите и переведите данные гнезда слов.

1. to expect, expectable, expectance, expectant; 2. to facilitate, facilities, facility; 3. heredity, hereditary, hereditarily; 4. part, partial, particle

Упражнение 6. Прочтите и переведите следующие словосочетания.

infectious desease, diseases of childhood, to suffer from a disease, disease incidence, an expectant mother, a hereditary disease, partial pressure

Упражнение 7. Просмотрите текст А и скажите, что было известно о вирусах до изобретения электронного микроскопа и что нового узнали о вирусах после его изобретения.

Text A Viruses

1. For three-quarters of a century, scientists have known that many diseases of man, animals, plants and even of microorganisms are caused by transmissible agents which cannot be seen under the light microscope, they are so small that they can pass through filters fine enough to hold back the most minute bacteria. These mysterious invisible agents were given the generic name of viruses. In the 1930's, two great discoveries were made which provided concrete informa- tion concerning the nature of viruses. It was found that some of them would be crystallized almost as readily as if they were ordinary chemical substances.

2. Chemically, the active virus particles were found to behave like giant molecules. At about the same time, the electron microscope became available and permitted pictures to be obtained of these crystals as well as of particles present in fluids and other materials having virus activity. Viruses would now be seen as concrete objects instead of being merely imagined.

3. The first unexpected fact revealed by electron microscopy was that the various viruses differ among themselves in shape and in size, as various types of bacteria. The virologist can differentiate between several types of viruses on the basis of their size and shape as revealed by electron micrographs. For example, the vaccinia virus is rather large. In contrast, the polioviruses are much smaller and yield very characteristic crystals. As to the tobacco mosaic virus, it can be crystallized in the form of thin needles having different lengths. The viruses that attack bacteria, which are called bacteriophages, are more complex, at least in

shape. Many of them have a thin tail and a large round or cylindrical head. Each active virus particle consists of at least two very different types of structural components. One structure made up of nucleic acid, carries the genetic hereditary characteristics of the virus. Another, protein in nature, is thought to protect this genetic apparatus and to facilitate its transfer from one infected cell to another. For example, electron micrographs revealed that virus of tobacco mosaic consisted of an inner constituent of nucleic acid lodged within an outer coat, cylindrical in shape and made up of protein. The central structure, the core, should be compared to the nucleus of ordinary cells in higher organisms, which also contains large amounts of nucleic acid and also carries the genetic endowment. In fact, the nucleic acid core of this virus is its most essential constituent. However, proteins and nucleic acids are not the only structural components of active viruses. Certain viral particles have recently been shown to contain lipids as part of their essential structures. High-magnification electron micrographs will reveal furthermore that some of them possess a distinct membrane. If we examined the structure of some of bacteria under highmagnification electron microscope we should see that they possess a distinct membrane.

Упражнение 8. Прочтите и переведите текст А. Первый и второй абзацы переведите письменно.

Упражнение 9. Найдите в тексте А ответы на следующие вопросы.

1. What have scientists known about viruses until the electrone microscope became available? 2. What two great discoveries were made in the 1930's? 3. Can the virologists differentiate between the types of viruses on the basis of their size or shape? 4. Are proteins and nucleic acids the only structural components of active viruses?

Упражнение 10. Составьте письменно план текста А.

Упражнение 11. Найдите в каждом абзаце текста А предложение, выражающее основную мысль данного абзаца, и переведите его.

Упражнение 12. Найдите в каждом ряду слово, синонимичное по значению первому слову ряда.

1. ordinary - everyday, common, usual, often, habitual; 2. to reveal- to detect, to open, to find, to show, to demonstrate; 3. remarkable - usual, seldom, unusual, interesting; 4. material - findings, essence,data, evidence, matter

Упражнение 13. Найдите в каждом ряду слово, противоположное по значению первому слову ряда.

1. inner - outside, out, outward, outer; 2. different - some, equal, something, the same; 3. to facilitate - to prevent, to hamper, to influence, to ignore; 4. within - out, outward, outer, out of, outside

Упражнение 14. Переведите следующие предложения. Определите функции глаголов: shall, should, will, would.

1. The most obvious properties of the ultramicroscopic viruses should be classified according to a) their invisibility with ordinary microscope; b) their refusal to multiply in artificial media; c) their ability to pass filters which hold back the smallest known bacteria. 2. In 1892 D. Ivanovski found that the sap of leaves attacked by mosaic disease would retain its infectious qualities even after filtration. 3. Before the middle of the nineteenth century the word «virus» would be commonly applied to all toxic or poisonous substances. 4. If you examined viruses in the electron microscope, you would see that the particles of each type of virus possessed a characteristic shape and size. 5. If the strains of virus to which people are subjected are too different from those in the vaccine, the vaccine will become useless. 6. They shall improve their method of investigation if they want to obtain good results.

Упражнение 15. Переведите на английский язык данные предложения письменно.

1. Вирусы вызывают заболевания у людей, растений и даже микроорганизмов. 2. Вирусы табачной мозаики образуют крис- таллы в форме тонких иголок различной длины. 3. Некоторые вирусы, как показали последние исследования, в своей структуре помимо белка и нуклеиновой кислоты содержат липиды и оболочки.

Часть II Слова к части II

Упражнения

Упражнение 1. Прочтите и переведите следующие слова.

destructive, microorganisms, chlorophyll, spores, to vary, variety, ocean, especially, polluted, alkaline, reservoir, mucus, mucous

Упражнение 2. Дайте исходные слова, от которых образованы следующие производные. Переведите их на русский язык.

1. occurrence, occurrent; 2. moisten, moisture, moistureless; 3. distinctly, distinction, distinctive, distinctively

Упражнение З. Прочтите текст текст В (10 мин). 1) Разделите его на 2 части соответственно вопросам:

1. What are bacteria?

2. Where do they occur?

2) Найдите и переведите: а) условные придаточные предложения, которые выражают маловероятные предположения; б) предложения с многозначными глаголами shall, will, should, would.

Text В What are Bacteria?

Bacteria rule the world. Man is dependent upon them from the day of his birth until the hour of his death. They are man's most useful servants and his most destructive masters. One is prone to ask: What are bacteria? Where do they occur? What are their functions?

Bacteria are minute single-celled living beings devoid of roots, leaves and stems. They are so small that they can be seen only with the aid of a powerful microscope; They are often spoken of as microorganisms. This term includes not only bacteria but all forms of life so small that you should require the microscope in their study. They are often referred to as germs or microbes. The early investigators considered them animals and would refer to them as «animalcules».

If we examined the bacteria we should find that they have many of the characteristics of animals. Some have the power of independent motion. All are devoid of green colouring matter, chlorophyll; most of them are compelled to live upon complex foods as do the animals. Their general structure, their methods of growth, their formation of threads and spores, and their simplicity in some of the lower forms of plant life, have caused the biologist to class them as plants. However, it is impos-

sible to make a clear-cut¹ distinction between some microscopical plants and some microscopical animals. The important thing to remember is that bacteria are the simplest forms of life, and partake of the characteristics of both plants and animals. For this reason, and for convenience, scientists agree to consider the bacteria with the plants.

Where do bacteria occur? Bacteria are widely distributed, occurring nearly everywhere. They are found in all natural soils, the number varying with the kind of soil, quantity of plant and animal debris present, moisture and treatment. They decrease in number with depth. Although they occur in air, it is not their natural home as under ordinary conditions they cannot grow and multiply in it. The number and variety found in air vary. The atmosphere of some high mountains and the air over the ocean far from shore may be free from bacteria. City and country air also differ from each other in the number and kind of bac- teria which they contain. There is a great variation in the air of buildings. Bacteria are especially numerous where dust is plentiful.

Most natural waters contain many bacteria. In sewage and polluted waters² they are especially numerous. If measures against pollution and contamination of water were not taken in time there would be much danger to people's health. They occur only in small numbers or not at all in deep wells³ and springs.⁴ A turbid stream, which contains the drainage of many cities, has a great variety and number of bacteria in opposition to the clear, rapid flowing water of uninhabited mountainous regions.

The intestines, owing to their alkaline reaction and the partly digested condition of their contents, are a great reservoir of bacteria. In the upper part there are few, but in the descending colon billions of bacteria are present. Sometimes they constitute one third of the total dry contents of the intestine. The health of the individual is determined by the number and kind of bacteria.

The normal tissues and the blood of animals are usually free from bacteria. If ordinary saprophytic bacteria entered the animal's body they would be ingested and destroyed by leukocytes. Microorganisms are rarely found on certain healthy mucous membranes, such as those of the kidneys, bladder and lungs. Occasionally they pass through the skin or the mucous membranes of the digestive tract after which they may be found for a short time in the blood. In certain diseased conditions the blood and tissues of man and lower animals become filled with bacteria.

Functions of Bacteria. The real significance of bacteria comes in the fact that we are living in a world filled with them. They cannot be kept out of the

alimentary tract. Considerable attention should be given to the favouring of the beneficial bacteria in man. The great Russian bacteriologist Mechnikov claimed that the rate with which man ages would be determined not by the years he has lived, but by the bacteria, which inhabit his digestive system.

Упражнение 4. Составьте схему распространения бактерий в природе. Расскажите о присутствии бактерий в природе, используя текст и схему.

Упражнение 5. Найдите в тексте предложения, более полно выражающие мысль данных суждений.

1. Man is dependent upon bacteria. 2. Bacteria are very small. 3. Bacteria are often spoken of as microorganisms. 4. They have many characteristics of animals. 5. Some characteristics of bacteria have caused the biologist to class them as plants. 6. We are living in a world filled with bacteria.

Часть III

Контрольно-обобщающие упражнения к уроку 14

Упражнение 1. Найдите условные придаточные предложения, которые выражают: а) маловероятное предположение; б) упущенную возможность совершить действие. Переведите предложения.

1. If you observed bacterial protoplasm under the optical microscope, it would appear simple in structure. 2. If the individual were in a healthy state, a large quantity of virulent microorganisms entering the body would be destroyed. 3. Certain water forms of bacteria, would die, if they were held above 30?C for more than a few minutes. 4. If bacteria had entered the body at the time of its active and unweakened condition they would have given it a very mild form of the disease. 5. It certian hygienie measures had been carried out we should have prevented the last year fatal epidemics.

(Ответ: а) 1, 2, 3. б) 4, 5. Если вы ошиблись, повторите ? 31 Грамматического справочника.)

Упражнение 2. Укажите, в каких предложениях слова shall, will, should,

would имеют модальное значение. Переведите эти предложения.

1. Great care should be taken in cultivating bacteria. 2. The water should be kept clean by filtration and safe by desinfection with chlorine

to destroy pathogenic and other forms of bacteria. 3. Pasteur could not believe that two compounds which acted so differently in one respect would be absolutely identical in every other way. 4. In the investigation of yellow fever it became necessary to find human volunteers who would risk contracting yellow fever. 5. They shall correct their mistakes themselves. 6. It will be difficult to diagnose this case.

(Ответ: 1, 2, 4, 5. Если вы ошиблись, повторите ? 33 Грамматического справочника.)

Упражнение 3. Дайте форму множественного числа от следующих слов:

bacillus, bacterium, coccus, foot, virus, genus, spirillum (Ответ: bacilli, bacteria, cocci, feet, viruses, genera, spirilla.)

Упражнение 4. Выберите правильное значение выделенных слов.

1. Bacteria may occur (происходить, случаться; встречаться) free or in aggregates. 2. The smallest bacteria are beyond the range (линия, ряд; предел) of our most powerful light microscopes. 3. The size of the microscopical organisms can be estimated by filtration, consequently they are referred to (направлять к ... ; упоминать; относить к ... ) as filtrable viruses. 4. Viruses attack all parts of the body except (исключая; помимо) the digestive system.