Часть 2 чтение-перевод Unit 3

Прочитайте следующие слова

tissue

nucleus

cell

vacuole

thick

chlorophyll

cellulose

vital

cytoplasm

view

The Biology of Plant Life.

General Structure of Plants. - No matter how simple or how complex a plant may be, it can exist only if it carries on the several life processes. The higher plants, like animals, are made up of organs, such as the roots, stem, leaves, flowers, and usually the fruit. The organs of plants are made up of tissues, and the tissues are made up of cells. Cells vary greatly in size and shape even in the same tissue and even more so in different plants. The separate cells of a tiny plant, Pleurcoccus, are nearly spherical, and so small as to be invisible without the aid of a microscope. Others, like root hairs are very long and slender in shape and large enough to be seen by the naked eye.

The Three Parts of the Plant Cell. - All cells have three main parts. These are (1) the wall. The wall in a plant cell is usually thicker and firmer than the wall in animal, because of the presence in plants of a substance known as cellulose, a carbohydrate. (2) The wall in every cell encloses a mass of cytoplasm, the second main part of a cell. In the cytoplasm is imbedded (3) the nucleus, the third main part of a cell.

The nucleus is darker than the surrounding cytoplasm. Besides the wall, the cytoplasm, and the nucleus, a plant cell usually contains spaces called vacuoles, filled with cell sap, and if the cell is green, it contains small green particles, called chlorophyll bodies or chloroplasts. In the plant as in the animal the cell is the unit of structure and of function of all living parts.

Protoplasm. - The entire cell is composed of protoplasm or substances made by it. This has one form in the wall, another in the cytoplasm, and still another in the nucleus. Cytoplasm is that particular kind of protoplasm which is surrounded by the cell wall. It is the agent that, for the most part, carries on the vital processes of the plant. The nucleus is still another kind of protoplastm which is very important in the life process of the cytoplasm, especially in reproduction.

Not all plants, however, are large, have green leaves, and produce food for man and animals as does the apple tree. The biology of plants or botany requires that we take a broader view of plants and how they live. In this richly varied world there are plants like trees, some of which are the largest living things, and small plants, thousands of which can live in a small drop of liquid; plants that are green and those that lack green color; helpful plants that man cultivates, and harmful ones that he tries to get rid of; plants that live only in water, and those that live only on land; plants that produce flowers and fruit, and others that do not; plants that live for hundreds of years and plants that live for only a few hours; plants that like abundance of sunshine, and those that prefer dim light.

Green plants are so common that you may never have stopped to think how wonderful and important they are. A good way to begin our general study of plants is to compare them with animals. If you have ever tried to raise plants in the house or garden, you know that, like animals, they cannot live without water, air, food, light, and a moderate amount of heat. Like animals too they are of different shapes, sizes, and colors, and perform all the life processes in passing through the life cycle. In fact, the differences are not so many as the likenesses, although they are more apparent, for only three are important; namely, they are not conscious, they are unable to move about, and they make their own food, but they are the only food-makers in the world, a fact which gives them an importance which no other organisms have. In making food for themselves and animals, they also, incidentally, help animals in two other ways, as we shall see later.

Although we are familiar with green flowering plants in a general way, we should not think of them as the only plants that exist. In biology the apple tree and other flowering plants are considered highly specialized forms of plant life. Many plants do not produce flowers, nor even have roots, stems, or leaves. Such are the molds that grow on decaying fruit and bread, the bacteria that cause disease, the green scum that floats on ponds, and the mosses and mushrooms in the woods, to mention only a few.

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Задание 1.

Дайте русские эквиваленты следующих слов:

to carry, vary, exist, be made up of, enclose, fill with, be composed of, lack, get rid of, prefer, compare, consider, cause;

tissue (n), cell, no matter how, root hairs, aid, by the naked eye, cellulose, carbohydrate, cytoplasm, unit, nucleus (nuclei), abundance, amount, bacterium(bacteria). disease; moss;

complex(a), slender, tiny, separate, invisible, firm, main, moderate.

Задание 2.

Образуйте множественное число следующих существительных:

nucleus, bacterium, phenomenon, species, stimulus, foot, goose, fungus, tooth, man, woman, crisis, mouse, wolf.

Задание 3.

Переведите следующие предложения на русский язык:

1. What is the matter with him ?

1. It made no matter to him that his brother lost all his money.

1. It does not matter if I miss my train, there is another one later.

1. It maters a good deal to me.

1. It's a matter of great concern to us.

1. No matter what he thinks I'll do it.

1. It's a matter of common knowledge.

1. No matter how simple or how complex a plant may be, it can exist only if it carries on the several life functions.

Задание 4.

Употребите ( must, must not, had to, needn't, don't have to) в следующих предложениях:

1. A soldier ... obey orders.

1. I think we ... pay in advance.

1. Jane ... go to school yesterday.

1. Passengers ... ... speak to the driver.

1. Saturday is my day off. I ... ... to work.

1. Students ... leave bicycles in front of the library.

Задание 5.

Слова для запоминания:

to grow ( grew, grown ), vary, be made up of, enclose, be composed of, cause (v, n), get rid of;

tissue (n), cell, by the naked eye, amount, disease, moss, mushroom, sap;

no matter how, no matter what, besides.

Задание 6.

Ответьте на вопросы по тексту:

1. What are higher plants made up of ?

1. What are the organs of plants composed of?

1. What are the three parts of the plants cell?

1. How do we call small green particles in the green cell?

1. What is cytoplasm?

1. In what life process is the nucleus very important?

1. How do plants differ in size?

1. Do all plants produce flowers?

Задание 7

Подготовьте сообщение по теме:

1. General structure of plants.

1. The three parts of the plant cell.

1. Protoplasm.

1. Speak about flowering and non-flowering plants.