Living Organisms and their Environment

Part I

An organism's surroundings and all the factors which influence it constitute its environment. The complex relations between the organisms and their environment can be seen in a very brief consideration of food supply.

The green plants are at the base of the system of food relations in the organic world. They take from their surroundings only simple inorganic materials - water, carbon dioxide, oxygen, inorganic nitrogen, and various mineral salts. From these simple substances plants build carbohydrates, fats and proteins.

Oxygen is an absolute requirement for most organisms; it is likewise abundant in most surroundings. Land-dwelling species obtain oxygen from the air; most aquatic species utilize the oxygen dissolved in water. If as sometimes happens in experimental or otherwise limited environments the oxygen supply of organisms is cut off the organisms will die.

Quite as important as oxygen is water which is a universal component of protaplasm. It provides the essential medium for the chemical processes of life and the transport of materials. The amount of water available determines what types of organisms will occur in an environment, how fast they will grow, and the rate of many of their basic life processes.

Carbon dioxide in the environment is essential for photosynthesis. If either carbon dioxide or inorganic nitrogen is absent or deficient the growth of photosynthetic plants is limited or prevented. This, in turn, affects the animal population.

Упражнение l. Прочитать, перевести заголовок текста. О чем идет речь?

Упражнение 2. а) Догадаться о значении интернациональных слов:

n adj

animal process absolute experimental

air protoplasm aquatic mineral

base protein basic universal

component plant organic v

factor species inorganic to affect

material system photosynthetic to constitute

medium substance chemical to determine

organism transport complex to limit

photosynthesis type deficient to prevent

population essential to utilize

б) Произнести за диктором названия химических элементов:

carbon dioxide – углекислый газ oxygen – кислород

nitrogen – азот carbohydrate – углевод

Упражнение 3. Произнести за диктором новые слова. Ознакомиться с их переводом.

1. surroundings - среда

2. to influence – влиять, влияние

3. to supply - снабжать

4. requirement - требование

5. abundant – имеется в изобилии

6. species – вид, разновидность

7. to dwell – жить, обитать, находиться

8. to obtain - получать

9. to dissolve - растворять

10. essential - необходимый

11. medium - условия

12. to prevent – предотвращать

Упражнение 4. Прочитать текст, используя новую лексику, и ответить на следующие вопросы:

1. What are the main components of the environment?

2. What do green plants take from their surroundings? What for?

3. What is oxygen important for?

4. What does the amount of water available determine?

5. What is carbon dioxide essential for?

6. What happens in the environment without oxygen (water, carbon dioxide) supply?

Упражнение 5. Рассказать о компонентах окружающей среды, используя данные конструкции:

The green plants   Living organisms   Land-dwelling species   Aquatic species   Oxygen   (amount of) water   Carbon dioxide

is are constitute determine (s) affect influence build take utilize obtain provide (s) will die

- water, carbon dioxide, oxygen, inorganic nitrogen and mineral salts from the surroundings; - at the base of the system of food supply; - carbohydrates, fats, proteins simple inorga­nic materials; - the absolute requirement for the most organisms; - without oxygen; - a universal component of protoplasm; - the essential medium for the chemical pro­cesses of life; - requirement for the most organisms; - the transport of materials; - abundant in most surroundings; - the oxygen dissolved in water; - oxygen from the air; - essential for photosynthesis;

Упражнение 6. 1) Рассказать, какую новую информацию вы узнали о живых организмах из текста? 2) Выбрать ключевые слова и составить по ним конспект текста.