polunina_ln_bobrovskaia_im_priroda_nauka_tekhnologii

LANGUAGE IN USE

7. Read the article about cells and put the verbs in brackets in the correct form.

Cells

Living organisms, from aardvarks and apple trees to zebras and zinnias, (1) … (be composed) of cells. Living organisms, including each of us, generally (2) … (begin) life as a single cell, which (3) … (divide) repeatedly until it develops into an organism consisting of perhaps billions of cells.

During the first few hours of any organism’s development, the cells

(4) … (resemble) each other, but changes soon (5) … (occur), not only in the appearance of the cells but also in their function. The modifications of some, for example, (6) … (permit) them to serve as conducting cells, while others come to function in secretion or support. Some cells (7) … (live) and function for many years; others mature and

(8) … (degenerate) in just a few days. Even as you read this, millions of new cells (9) … (be produced) in your body. Some cells (10) … (add) to your total body mass (if you (11) … yet … (stop) growing), but most replace the millions of older cells that (12) … (be destroyed) every second you remain alive. The variety and form of cells (13) … (seem) almost infinite, but certain features (14) … (be shared) by most of them.

(Adapted from Stern, K.R. Introductory Plant Biology)

8. Use the word given in capitals at the end of each line to form a word that fits in the space in the same line. There is an example at the beginning. Example: (0) treatment.

Gene Therapy

Gene therapy, experimental medical (0) …, TREAT manipulates a gene or genes within cells in order to

produce proteins that change the function of those cells.

Gene therapy originated in efforts to treat and

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desire.

(Adapted from Microsoft Encarta, 2008)

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9. Arrange the parts of the text in logical order so that the text was complete.

Vitamin

(1)The various vitamins are not chemically related, and most differ in their physiological actions. They generally act as catalysts, combining with proteins to create metabolically active enzymes that in turn produce hundreds of important chemical reactions throughout the body. Without vitamins, many of these reactions would slow down or cease.

(2)The body can manufacture only vitamin D; all others must be derived from the diet. Lack of them causes a wide range of metabolic and other dysfunctions. In the U.S., since 1940, the Food and Nutrition Board of the National Research Council has published recommended dietary allowances (RDA) for vitamins, minerals, and other nutrients.

(3)Vitamins are any of the organic compounds required by the body in small amounts for metabolism, to protect health, and for proper growth in children. Vitamins also assist in the formation of hormones, blood cells, nervous-system chemicals, and genetic material.

(4)Expressed in milligrams or international units (IU) for adults and children of normal health, these recommendations are useful guidelines not only for professionals in nutrition but also for the growing number of families and individuals who eat irregular meals and rely on prepared foods, most of which are now required to carry nutritional labeling.

(5)The 13 well-identified vitamins are classified according to their ability to be absorbed in fat or water. The fat-soluble vitamins – A,D,E, and K – are generally consumed along with fat-containing foods, and because they can be stored in the body’s fat, they do not have to be consumed every day. The water-soluble vitamins – the eight B vitamins and vitamin C – cannot be stored and must be consumed frequently, preferably every day (with the exception of some B vitamins).

(6)A well-balanced diet contains all the necessary vitamins, and most individuals who follow such a diet can correct any previous

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vitamin deficiencies. However, people who are on special diets, who are suffering from intestinal disorders that prevent normal absorption of nutrients, or who are pregnant or lactating may need particular vitamin supplements to bolster their metabolism.

(Adapted from Microsoft Encarta, 2008)

SPEAKING

10. Do you agree with the following statement? Give reasons to support your answer.

Most biologists accept the estimate of American evolutionary biologist Edward O. Wilson that the Earth is losing approximately 27,000 species per year. This estimate is based primarily on the rate of disappearance of ecosystems, especially tropical forests and grasslands, and our knowledge of the species that live in such systems.

11. Give more examples of ecosystems. Using your own words, try to define the term “ecosystem”. Why do ecosystems disappear? What do you think the main destroying force is?

WRITING

12. Arrange the following vitamins into two groups and fill in the table. Use the information in task 10.

Vitamins: C (Ascorbic Acid), A, B1 (Thiamine), Biotin, D, B2 (Riboflavin), Folic Acid, K, B3 (Nicotinic Acid), B5 (Pantothenic Acid), E, B6 (Pyridoxine), B12 (Cobalamin)

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13. Choose one of the vitamins and describe it briefly using the following scheme:

1.vitamin

2.food sources

3.health benefit

4.deficiency

KEY WORDS

adaptation, animals, assimilation, attribute, biodiversity, birds, cells, characteristic, cure, digestion, disease, ecosystem, environment, estimate, extinction, fat-soluble, feature, form, function, fungi, gene, growth, habitat, human, inhabit, inheritance, living organism, living thing, mammals, metabolic activities, metabolism, microorganisms, molecule, nucleus, plants, protoplasm, reaction, reproduction, reptiles, respiration, response, species, structural units, structure, therapy, tissue, treat, variety, vitamin, water-soluble

SUPPLEMENTARY READING

Biological Diversity

(1)Biodiversity or Biological Diversity is the sum of all the different species of animals, plants, fungi, and microbial organisms living on Earth and the variety of habitats in which they live. Scientists estimate that upwards of 10 million – and some suggest more than 100 million – different species inhabit the Earth. Each of species is adapted to its unique niche in the environment, from the peaks of mountains to the depths of deep-sea hydrothermal vents, and from polar ice caps to tropical rain forests.

(2)Biodiversity underlies everything from food production to medical research. Humans use at least 40,000 species of plants and animals on a daily basis. Many people around the world still depend on wild species for some or all of their food, shelter, and clothing. All of our domesticated plants and animals came from wild-living ancestral species. Close to 40 percent of the pharmaceuticals used in the United

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States are either based on or synthesized from natural compounds found in plants, animals, or microorganisms.

(3)The array of living organisms found in a particular environment together with the physical and environmental factors that affect them is called an ecosystem. Healthy ecosystems are vital to life. They regulate many of the chemical and climatic systems that make available clean air and water and plentiful oxygen. Forests, for example, regulate the amount of carbon dioxide in the air, produce oxygen as a byproduct of photosynthesis (the process by which plants convert energy from sunlight into carbohydrate energy), and control rainfall and soil erosion. Ecosystems, in turn, depend on the continued health and vitality of the individual organisms that compose them. Removing just one species from an ecosystem can prevent the ecosystem from operating optimally.

(4)Perhaps the greatest value of biodiversity is yet unknown. Scientists have discovered and named only 1.75 million species – less than 20 percent of those estimated to exist. And only a fraction of those identified has been examined for potential medicinal, agricultural, or industrial value. Much of the Earth’s great biodiversity is rapidly disappearing, even before we know what is missing. Most biologists agree that life on Earth is now faced with the most severe extinction episode since the event that drove the dinosaurs to extinction 65 million years ago. Species of plants, animals, fungi, and microscopic organisms such as bacteria are being lost at alarming rates – so many, in fact, that biologists estimate that three species go extinct every hour. Scientists around the world are cataloging and studying global biodiversity in hopes that they might better understand it, or at least slow the rate of loss.

(Adapted from Microsoft Encarta, 2008)

1. Read the text and decide whether the following statements are TRUE, FALSE or there is NO such INFORMATION in the text.

2. Decide which part of the text contains the following information.

1.Scientists have discovered and named less than 20 percent of existing species.

2.Healthy ecosystems are essential for life.

3.Give the answer to the following question.

Why are healthy ecosystems vital to life?

1.They regulate none of the chemical and climatic systems that make available clean air and water and plentiful oxygen.

2.They regulate many of the chemical and climatic systems that make available clean air and water and plentiful oxygen.

3.They regulate many of the chemical and climatic systems that make the air clean.

4.They regulate many of the chemical and climatic systems that make available clean air and water and plentiful hydrogen.

4. What is the main idea of the text?

1.Many people around the world still depend on wild species for some or all of their food, shelter, and clothing.

2.Biodiversity underlies everything from food production to medical research.

3.Scientists around the world are cataloging and studying global biodiversity in order to understand it, or at least slow the rate of loss.

4.Scientists have discovered and named only 1.75 million species – less than 20 percent of those estimated to exist.

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UNIT 6

HEALTH

WARMING UP

1.Medical science tells us that what we eat is important for our health. Give examples of healthy and unhealthy foods and drinks that you like.

2.What are your eating habits? When do you eat? What are your favorite foods?

3.What are your favorite kinds of exercise and favorite sports? Which activities do you enjoy doing in summer?

4.Do you consider your lifestyle to be healthy or unhealthy?

READING

Human beings require food to grow, reproduce, and maintain good health. Without food, our bodies could not stay warm, build or repair tissue, or maintain a heartbeat. Eating the right foods can help us avoid certain diseases or recover faster when illness occurs. These and other important functions are fueled by chemical substances in our food called nutrients. Nutrients are classified as carbohydrates, proteins, fats, vitamins, minerals, and water.

Once digested, carbohydrates, proteins, and fats provide the body with the energy it needs to maintain its many functions. Scientists measure this energy in kilocalories, the amount of energy needed to raise 1 kilogram of water 1 degree Celsius. In nutrition discussions, scientists use the term calorie instead of kilocalorie as the standard unit of measure in nutrition.

When the body is not given enough of any one of the essential nutrients over a period of time, it becomes weak and less able to fight infection. The brain may become sluggish and react slowly. The body taps its stored fat for energy, and muscle is broken down to use for energy. Eventually the body withers away, the heart ceases to pump properly, and death occurs – the most extreme result of a dietary

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condition known as deficiency-related malnutrition.

Deficiency diseases result from inadequate intake of the major nutrients. These deficiencies can result from eating foods that lack critical vitamins and minerals, from a lack of variety of foods, or from simply not having enough food. Malnutrition can reflect conditions of poverty, war, famine, and disease. It can also result from eating disorders, such as anorexia nervosa and bulimia.

Although malnutrition is more commonly associated with dietary deficiencies, it also can develop in cases where people have enough food to eat, but they choose foods low in essential nutrients. This is the more common form of malnutrition in developed countries such as the United States. When poor food choices are made, a person may be getting an adequate, or excessive, amount of calories each day, yet still be undernourished. For example, iron deficiency is a common health problem among women and young children in the United States, and low intake of calcium is directly related to poor quality bones and increased fracture risk, especially in the elderly.

A diet of excesses may also lead to other nutritional problems. Obesity is the condition of having too much body fat. It has been linked to life-threatening diseases including diabetes mellitus, heart problems, and some forms of cancer. Eating too many salty foods may contribute to high blood pressure (see hypertension), an often undiagnosed condition that causes the heart to work too hard and puts strain on the arteries. High blood pressure can lead to strokes, heart attacks, and kidney failure. A diet high in cholesterol and fat, particularly saturated fat, is the primary cause of atherosclerosis, which results when fat and cholesterol deposits build up in the arteries, causing a reduction in blood flow.

(Adapted from Worthington-Roberts, B. Human Nutrition, Microsoft Student 2008)

Expand your vocabulary

to maintain – поддерживать nutrition – питание; пища

to digest – переваривать; усваивать to measure – измерять

amount – количество

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essential – существенный; необходимый sluggish – медленный, вялый; медлительный to wither – сохнуть; ослабевать

to cease – прекращать(ся) famine – голод

to undernourish – недокармливать fracture – перелом

excess – избыток

obesity – тучность; ожирение pressure – давление reduction – снижение

POST-READING ACTIVITY

1. Discuss the following questions.

1.What are nutrients? How are they classified?

2.Using your own words, try to explain what kilocalorie is.

3.What happens to our body if it is not given enough of any one of the essential nutrients over a period of time?

4.What do deficiency diseases result from? Define what malnutrition is.

5.Can a diet of excesses lead to nutritional problems? Give specific examples to support your answer.

2. Put a circle round the transcription sign that matches the sound underlined in the word. All the words begin with the letter ‘w’.

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