IX. Read the following passages, without a dictionary and reproduce them in

Russian to your classmates. Work in pairs:

a) Visitors to Khosta, a resort on the Black Sea Coast, always go to see the great

silver poplar, that grows there. Ten people with joined hands can just encircle the

tremendous tree, rising sixty five metres above the ground. The unique plant is at

least 160 years old.

b) Deep in the sea it is always dark,, for sunlight cannot reach down more than about a half mile. The only light in all this vast darkness is made by'animals them13 selves. Certain squid which are cousins of octopuses, swim in schools and keep together by means of coded flashing lights. Many kinds of deepsea fish have lights on their bodies. It is believed that thith beaming of light helps them to recognize their own kind.

c) Scientists know that all living organisms are luminous. But why? Hundreds of guesses were made and thousands of experiments staged. Now Moscow scientists,

supervised by Academician N. Semyonov, have established that luminosity of living organisms is their mode of jettisoning excessive energy, of "letting off steam", so to speak. Is there any practical use to be had from the discovery? Yes. It was established that the luminosity of the organisms is connected with their general condition. Cells affected by cancer, for example, are less luminous than healthy ones. Thus one more method of discovering the presence of that illness has been found.

d) Plants are sensitive to sound. Indian botanists have proved that by subjecting plants to sound of definite pitch, it is possible to stimulate or hinder their growth. A seven-year experiment showed that rice and tobacco are the most "musical" plants.

X. Read the text “Animal – plant differences” from the “Texts for home reading”

XI. Give the main points of all the texts in Russian. Write a breif summary of the texts in English. Be prepared to speak on the topic "Differences and Similarities between plants and animals".

IMPROVEMENT OF PLANTS

All varieties of crops have some desirable characteristics or they would not be used. Nevertheless, each of these varieties is known to possess one or more undesirable traits which, if eliminated, would result in higher yields and better quality. The aim of the plant breeder is to develop superior varieties by eliminating the undesirable characteristics and combining the desirable ones in the same variety.

Plant improvement is based on the principles or laws of heredity which are included in the science known as genetics. Many of the principles and techniques

used in plant breeding are complex and to understand them fully intensive study and training are required. Selection is a simple, but important method of improving plants. As the name suggests this method consists of selecting the outstanding types and discarding those that are undesirable because of certain characteristics being possessed by them. For example, in small grains, plants resistant to lodging may be selected; and with alfalfa those capable of surviving in severe winters are to be retained. After a period of testing, during which plants are selected for certain desired traits or characteristics, a superior strain may be developed. Improvement by selection cannot be accomplished, however, unless the variety from which the selections are being made possesses some plants containing the characteristics desired.

Selection is not a new method of improving plants. Actually this process is as old as plants themselves. For many thousands of years plants have been subjected to the stern and relentless forces of nature, and only the fittest is left entirely to nature, the process is extremely slow. Man cannot wait for nature alone to improve plants for him. By selecting superior plants, he is able to bring about improvements in a few years that would require thousands of years of time if left to nature alone. Two procedures are commonly used when new varieties are developed by the process of selection. They are referred to as mass selection and individual selection. . Mass selection consists of selecting a fairly large number of individual plants possessing the desired characteristics. The seed from such plants is then mixed and sown together, and the better individuals are again selected or the poorer ones discarded. This process of selection is to be repeated for a few years until the plants prove to be reasonably uniform for the qualities desired Individual plant selection is commonly referred to as pedigree or pure-line selection. When this method is used, individual plants are selected that are superior for certain characters but instead of mixing the seed as in mass selection, the seed from each head or individual is planted in a row of its own in such a manner as to keep the progeny of each parent separate. The progeny of each plant are then carefully observed, a record being made of their appearance and performance. Comparisons between the different progenies are made, those with undesirable

characters being discarded.

Records of performance are carefully checked and compared each year with

those of standard varieties which are also grown under the same conditions. If after a testing for a number of years, the strain proves to be superior to the standard varieties, it is then grown in larger plots to increase the supply of seed. A period of several years may be required for sufficient seed to be obtained for general distribution to farmers. As a rule, 8 to 14 years are usually required for making

the selection, testing it and increasing it to the point where the new variety can bereleased to farmers.

Notes to the text:

1. as the name suggests—как указывает само название

2. whichever is most convenient — что является наиболее удобным

3. in a row of its own — на своем ряду

4. that are superior for certain characteristics — которые являются лучши-

ми в отношении опреде ленных качеств

5. he used to work — он имел обыкновение работать

EXERCISES

I. Give all the derivatives of the following words:

To cover, to explore, to direct, to adapt, to situate, to act, to mix, to desire, to

use, to vary, to select, to refer, to consist, to repeat, to plant, to separate

II. Find synonyms for fhe following words in the text:

To wish, to have, different, to give, task, better, to combine, well-known, to fit,

right, experiment, base, to use, together with, possibility, on condition