Hardwood; layer of cells; nutrients; seedling; sieve tubes.

1. In the spring, when the soil gets warm enough and moisture is

abundant, deep changes begin to take place in the … seed.

2. The …, whose part is to direct and hasten living processes, start

their work feverishly.

3. The stored proteins are split by the enzymes into some 20 soluble

compounds called ….

4. … is partly used for building the body of the tree and partly burned

up to provide necessary energy for the process.

5. The root has important work to do, it provides water for the young

….

6. The tree has to depend on the … available in that particular place.

7. The cambium consists of a single … that retain their capacity to divide

throughout the life of the tree.

8. In the soft inner bark, or bast, are formed …, through which manufactured

sugar dissolved in water flows from the foliage to storage tissues

in stem and root.

9. The alternation of spring wood and summer wood causes the concentric

structure of the tree trunk known as ….

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10. In the cross section of the … trees there may be seen numerous

dots, so-called vessels.

11. The most important ingredient, sixty percent of the wood of a

tree is ….

12. The function of the root is to provide water and minerals for the

tree and to … it securely to the ground.

TEXT 2. WOOD IN THE MAKING

Read text 2 and 1) give definitions to the words in italics and 2) answer the following

questions:

- What is the function of the leaf?

- What is the function of the cambium?

- What is the function of the root?

Like all green plants, trees make the materials for growth in their

leaves by a process known as photosynthesis. Deriving its energy from

sunlight, it is a complex chemical reaction in which carbon dioxide from

the air combines with water taken from the ground to form sugars. The reaction

takes place in the presence of chlorophyll — the green substance

which gives leaves their characteristic colour.

Carbon dioxide passes directly into the leaf through tiny openings

called stomata, but the water has a long journey from the ground to the

chemical factory in the leaf. It passes into the roots through the root hairs

by osmosis — the flow of water from a solution of low salt concentration,

as is normal in the ground, to one of high salt concentration, as in the hair

cell. The sap then flows through the xylem, or sapwood, to the crown of

the tree.

But wood has other important functions in addition to the conduction

of sap. It provides mechanical strength to support the weight of the crown

of the tree, and stores food created by the leaves. Food is moved in solution

from the leaves, to all parts of the tree through the inner bark, or

phloem, and is used, either immediately or after a period of storage for the

generation of new growth.

New wood is produced by a specialized cell layer called the cambium,

lying between the wood and the phloem. The wood cambium is completely

enclosed in the living parts of the tree and during the periods of active

growth the cambial cells divide to produce new wood cells on the inside

and phloem cells on the outside; thus new wood is laid down on a core of

existing wood. If part of the year is unfavourable for growth because of

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cold or drought, wood is laid down as seasonal increments which are seen

as growth rings. If growth is continuous, as in tropical regions, no growth

rings are produced in the wood. Two important functions, sap flow and

food storage, occur in the most recently formed wood, called sapwood.

However there comes a time when the innermost sapwood is so far removed

from the active growth region that it dies and the cell contents undergo

chemical change. The new substances produced may colour the

wood to form a distinctive heartwood.

Majestic Maturity

The tree has the longest life-span of all Earth’s higher forms of life

and during its life may produce literally millions of progeny. To maintain

its remarkable existence it has highly specialized organs. The roots anchor

the trees in the earth and absorb water and mineral salts. The stem conducts

the nutrient sap to the leaves, where food is manufactured, and then

carries the food to all parts of the tree. Fruits produced each year ensure

the healthy survival of the species.

The leaf

The leaf has a protective outer layer, the epidermis, a middle mesophyll,

which contains the chloroplasts needed for photosynthesis; and the

central vascular bundles of xylem and phloem cells, which carry nutrients

to and from the leaf.

Stem

A tree grows in thickness by the activity of a single layer of cells

called the cambium. This produces sapwood, or xylem, on the inside, and

bark, or phloem, on the outside. As the cambium continually divides, the

first-formed xylem cells become progressively detached from the cambium,

undergoing chemical and physical changes to form the distinctive

heartwood.

Root

Small hairs on the roots extend into soil and take up moisture by the

process of osmosis. Mineral salts essential to growth are also absorbed and

pass into the water stream. The solution enters the xylem vessels of the

roots and is distributed throughout the tree. Ninety-nine per cent of the water

is lost through the stomata of the leaves by evaporation. There is, therefore,

a continuous movement of water through the tree and on a summer

day an oak may take up more than 100 gallons.

Note: 1 gallon = 4, 546 л (Великобритания) или 3,785 л (США).

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Topical Vocabulary

photosynthesis [，fǩutǩ'sinθǩsǺs] — фотосинтез;

chlorophyll ['klǤrǩfǺl] — хлорофилл;

stoma ['stǩumǩ] (pl. stomata) — устьице (дыхательное отверстие листа);

root hairs — корневые волоски;

osmosis [Ǥz'mǩusǺs] — осмос;

hair cell — волосовидная клетка;

sap — заболонь; сок растений;

sapwood — заболонь древесины;

xylem ['zaǺlǩm] (= sapwood) — ксилема (основная проводящая ткань);

crown of the tree — крона дерева;

conduction of sap — проводимость сока;

inner bark (phloem) — внутренний слой коры;

cambial ['kambǺǩl] cells — клетки камбия;

phloem ['flǩuǩm] cells — клетки флоэмы;

core — сердцевина, ядро;

seasonal increment ['ǺŋkrǺmǩnt] — сезонный прирост;

sap flow — передвижение сока;

food storage — запас питательных веществ;

the innermost sapwood — самый глубокий слой заболони;

cell contents ['kǤntǩnt] — содержимое клетки;

to colour wood — окрашивать древесину;

heartwood ['ha:twud] — сердцевина, ядро; ядровая древесина;

progeny ['prǤdȢǩnǺ] — потомство;

mineral salts — минеральные соли;

maturity [mǩ'tjuǩrǺtǺ] — созревание; зрелость;

nutrient ['nju:trǺǩnt] sap — питательный сок;

outer layer — внешний, наружный слой;

epidermis [,epǺ'dǫ:mǺs] — эпидермис, кожица (наружная покровная ткань листа);

mesophyll ['mesǩu,fǺl] — мезофилл (фотосинтезирующая паренхима);

chloroplast ['klǤrǩu,plast] — хлоропласт (зеленые пластиды растительной клетки);

vascular ['vaskjulǩ] bundle — сосудистый пучок;

xylem ['zaǺlǩm] vessels — сосуды ксилемы;

evaporation [Ǻ,vapǩ'reǺ∫n] — испарение.

EXERCISES

Exercise 7. Match the word (numbers 1—12) with its definition (letters

A—L).

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1. photosynthesis A. the juice which circulates through the woody plant carrying

water, food, etc.

2. phloem B. the green substance which gives leaves their characteristic

colour

3. osmosis C. the cell layer lying between the wood and the phloem, from

which new bark and wood develop

4. cambium D. the hard wood at the core of a tree trunk

5. stomata E. the woody tissue through which the sap flows

6. chlorophyll F. the most recently formed wood responsible for sap flow and

food storage

7. heartwood G. seasonal increments which are seen in the cross section of

the tree

8. xylem H. tissue which provides mechanical strength to support the

weight of the crown of the tree (having some other functions

too)

9. sap I. a complex chemical reaction in the leaves by which all green

plants make the carbohydrates for growth from water and carbon

dioxide

10. growth ring J. the inner bark, the cell tissue serving as a path for the distribution

of nutrients in the plant

11. sapwood K. tiny openings in the leaf taking in carbon dioxide; breathing

pores in plants

12. wood L. the flow of water from a solution of low salt concentration,

as is normal in the ground, to high salt concentration, as in the

hair cell

Exercise 8. Translate the sentences into Russian. Pay attention to the

functions of the verb to be (notional verb, link verb, modal verb and auxiliary

verb).

1. What causes this awakening of life is not exactly known, and what

is known is complicated, indeed. 2. The growth hormone is activated; the

enzymes, whose part is to direct and hasten living processes, start their

work feverishly. 3. When growth conditions are favorable and food and

water are abundant, the rings are wide. 4. Most of the cellulose used at

present is converted into pulp and paper. 5. Lignin is not so useful as cellulose

at present, but there is little doubt that valuable products will be made

from it. 6. The function of the root is to provide water and minerals for the

tree and to anchor it securely to the ground. 7. New wood is produced by a

specialized cell layer called the cambium. 8. If growth is continuous, as in

tropical regions, no growth rings are produced in the wood. 9. The sapwood

is to perform two important functions, sap flow and food storage. 10.

The small hairs on the roots are extending into soil and taking up moisture

by the process of osmosis. 11. Small hairs on the roots extend into soil and

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take up moisture by the process of osmosis. 12. There is, therefore, a continuous

movement of water through the tree and on a summer day an oak

may take up more than 100 gallons.

Exercise 9. Translate the sentences with the modal verbs. Pay attention

to the form of accompanying infinitives.

1. As soon as the little root of a seedling penetrates the ground, the

tree is permanently anchored, for better or for worse, to the place, where,

unless it is transplanted, it has to stay all its life. 2. From now on the tree

has to depend on the nutrients available in that particular place and to develop

under climatic conditions found there, which cannot be changed. 3.

This alternation of spring wood and summer wood causes the concentric

structure of the tree trunk known as annual rings, they are seen clearly on

the cross section of a tree, one can determine fairly closely its age. 4. By

reading a cross section of an old tree, one can determine what growth conditions

prevailed during any particular year of the past. 5. In the cross section

of the hardwood trees there may be seen numerous dots. 6. This structure

of cellulose may be easily changed by action of even a weak acid, cellulose

then falls apart into the original dextrose molecules, providing an

enormous source of sugar that can be used for many purposes, from fattening

hogs to production of industrial alcohol. 7. The new substances produced

may colour the wood to form a distinctive heartwood. 8. The tree

has the longest life-span of all Earth’s higher forms of life and during its

life may produce literally millions of progeny. 9. There is a continuous

movement of water through the tree and on a summer day an oak may take

up more than 100 gallons. 10. The age of trees could be told by the rings of

the outer bark nearly as well as by those of the wood.

Exercise 10. Translate the sentences with the Participle (Participle I

and Participle II). Define their syntactical function (attribute, adverbial

modifier, part of the predicate).

1. In spring deep changes begin to take place in the dormant seed, already

conditioned by the low winter temperatures. 2. The insoluble stored

fats and starch begin to break down to soluble sugars, mainly dextrose. 3.

The stored proteins are split by the enzymes into some 20 soluble compounds

called amino acids. 4. In nature a seedling generally begins its life

in a place where its ancestors have been growing for a long time, so the little

tree is well adapted to the existing conditions. 5. The alternation of

spring wood and summer wood causes the concentric structure of the tree

trunk known as annual rings, they are seen clearly on the cross section of a

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tree. 6. Most of the cellulose used at present is converted into pulp and paper.

7. The rest of the wood consists mostly of lignin; which is a binding

material composed of carbon, oxygen, and hydrogen, but of an entirely different

and more complicated chemical structure than cellulose. 8. The total

length of all roots of a big spreading oak tree amounts to many hundreds of

miles. 9. Deriving its energy from sunlight, it is a complex chemical reaction

in which carbon dioxide from the air combines with water taken from

the ground to form sugars. 10. It provides mechanical strength to support

the weight of the crown of the tree, and stores food created by the leaves.

11. New wood is produced by a specialized cell layer called the cambium,

lying between the wood and the рhloem. 12. During the periods of active

growth the cambial cells divide to produce new wood cells on the inside

phloem cells on the outside; thus new wood is laid down on a core of existing

wood. 13. If growth is continuous, as in tropical regions, no growth

rings are produced in the wood. 14. Two important functions, sap flow and

food storage, occur in the most recently formed wood, called sapwood. 15.

Fruits produced each year ensure the healthy survival of the species.

Exercise 11. Translate the text into English, sentence by sentence.

Then speak about the anatomy of softwood and comment on the suggested

description.

Внутренняя анатомия стебля хвойных достаточно типична.

Большую часть его объема составляет древесина, а кора и сердцевина

развиты относительно слабо. Особенно это характерно для старых

деревьев. Вся ксилема хвойных состоит из трахеид, а сосуды у них не

обнаружены. Причем в течение тысячелетий происходило последова-

тельное уменьшение длины трахеид.

Подобно ксилеме, флоэму относят к сложным тканям, так как она

образована клетками нескольких типов. Основными из них являются

проводящие элементы флоэмы (ситовидные клетки). Если проводя-

щие элементы ксилемы образованы мертвыми клетками, то у флоэмы

они живые в течение всего периода функционирования. По флоэме

осуществляется отток веществ от фотосинтезирующих органов.

Между ксилемой и флоэмой располагается камбий, обеспечи-

вающий хвойным вторичное утолщение стебля. А поскольку в усло-

виях сезонного климата деятельность камбия зависит от времени го-

да, в стеблях большинства хвойных образуются хорошо выраженные

кольца ежегодного прироста древесины.

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