VIII. Match the sentence halves. Make complete sentences.

1.	Collenchyma and sclerenchyma make up tissues that	A	maintaining the shape of the leaf
2.	The cells are closely arranged and between each of them are	B	have a supportive structural role in plants
3.	Palisade cells are green colour due to	C	bringing water and mineral salts to the leaf
4.	Xylem forms the upper part of a vascular bundle in the leaf	D	minimizing water loss from the surface of the leaf
5.	Parenchyma cells are regarded as basic cells	E	from which other cells have evolved
6.	Each stomata is flanked by a pair of guard cells	F	air spaces connecting the mesophyll with the stomata
7.	The waxy cuticle is waterproof	G	the numerous chloroplasts they contain
8.	Leaves are made up of three main types of tissue	H	that regulate the size of the pore
9.	The veins provide mechanical support	I	epidermal tissue, vascular tissue and ground tissue
10.	The stalk holds the leaf in a position such that	J	its surface is exposed to the maximum amount of light

IX. Answer the following questions. Use all information given before.

1. What does the leaf shape provide?

2. How are the leaves arranged on many plants?

3. What is the role of the waxy cuticle?

4. Is the ground tissue the same as the epidermis, reproductive tissue and vascular tissue?

5. How are palisade cells packed?

6. What makes chloroplasts move around inside the cells?

7. Why are mature sclerenchyma cells not alive?

 

X. Read and translate the short text without any dictionary.

Fact of life:

The longest leavesbelong to palm trees. Those of the palm Raphia ruffia (from which raffia fibres are obtained) may reach over 22 m long.

XI. Food for thought

Leaves from different species have an enormous variety of size, shape, and structure. In addition to being adapted to absorbing light for photosynthesis, to what other factors might leaves be adapted?

XII. Translate into English using all the active possible.

1. Фотосинтез – это процесс, посредством которого, растения производят свою пищу.

2. Черешок удерживает лист в таком положении, чтобы поверхность листа получала максимальное количество света.

3. У многих растений листья на ветвях расположены таким образом, что они не затеняют друг друга.

4. Эпидермис представляет собой первую линию защиты листа от повреждений, инфекции и поедания животными.

5. Потеря воды с верхней поверхности листа более вероятна, т.к. она подвергается большему излучению солнца.

6. Сосудистая ткань состоит из жилок адаптированных к переносу жидких веществ ко всем частям растения.

7. Хлоропласты могут перемещаться внутри клеток в соответствии с количеством поступления света.

8. Пористый мезофилл – основное место газообмена в листьях.

9. Клетки располагаются свободно, и между каждой из них имеется воздушное пространство, соединяющее мезофилл с устьицем.

10. Колленхимные клетки являются удлиненными и стенки клеток имеют шероховатое утолщение и целлюлозу в уголках клеток.

Text 8.2. The Stem

■ Essential targets:

By the end of this text you should be able to:

● describe the structure of dicotyledonous stem;

● state the major functions of stems;

● explain how different tissues contribute to the mechanical support of stems.

Pre-reading

■ With a partner consider the following questions and try to answer them.

1. How do you think, what are the functions of stems?

2. What are distinguishable marks of all stems?

■ Read the given text and make your essential assignments:

Functions of a stem.

The stems of most plants are first and foremost organs of support. They lift terrestrial plants above the ground, raising their leaves towards the Sun and holding them in the best position to gain optimum exposure to light and carbon dioxide. They also hold flowers and fruit in positions that allow efficient pollination and seed dispersal.

As well as support, stems have three other major functions:

they transport materials from one part of the plant to another;

they produce new living tissue to replace cells that die and to make new growth;

they store food and water.

The stem as plant organ

The attachment site of a leaf or bud on a stem is called a node, and the po rtion between nodes is called an internode. Most stems point upwards from the ground and are easily distinguished from other plant organs. Some stems, however, have an unusual shape or location which makes them more difficult to identify. Potato tubers, for example, appear root-like, but they are actually swollen underground stems specialised for food storage. All stems, of whatever size, shape, or location, are distinguishable as such by the presence of nodes and internodes.