Translate the words in brackets and fill in the blanks. Translate the texts: How Trees Breathe
Acting as an enormous "carbon sink", trees soak up ____ (углекислый газ) from the air, producing life-giving ____ (кислород) in return. In fact, a medium-sized tree generates the same ____ (количество) of oxygen as each one of us needs to breathe.
In a tree, 'breathing' ____ (происходить) in the ____ (лист). Chlorophyll (the substance causing the green colour) absorbs the CO2 and uses it along with water to dissolve minerals taken up through the ____ (корни). After the chemical reaction is completed, the leaf releases oxygen and water vapor through its ____ (поры).
How Trees Drink
There are two ways that a tree can take in water: ____ (через) the leaves and through the roots.
Trees absorb small amounts of ____ (влага) from the air through their leaves and their ____ (кора). Most of their water, however, comes via the roots.
Water enters the roots through thin membranes at their ____ (кончики). The tree’s ____ ____ (васкулярная система) draws the water up through the ____ (ствол) and distributes it to the leaves. The leaves use the water to ____ (растворять) minerals. Excess water goes back to the air through pores in the leaf - a process called ____ (транспирация).
Read Text a and answer the question:
– What tree has a very thin bark?
Text a Structure of a Tree
The tree is composed of an underground part, the roots, and two aboveground parts, the trunk (bole) and the crown.
Leaves
The leaves convert carbon dioxide into oxygen and provide the tree with energy to grow and fight diseases. Leaves perform two vital functions for trees. They produce sugars by photosynthesis and they allow for the distribution of water through transpiration.
Photosynthesis is a process by which CO2 and water are combined with sunlight and a pigment called chlorophyll. The chemical reactions result in the production of sugars which provide energy to the tree. The leaves use some of this energy, but the majority is transported, in the form of sugar solutions, to other parts of the tree that require it.
Transpiration, or water loss, also takes place in the leaves. As this occurs, water is drawn up from the roots through the vascular system to replace lost moisture.
Roots
Roots are organs that provide structural stability for trees. Roots also absorb water and
minerals.
Root Structure
Roots are made up of a number of specialized components. The root hairs, tiny structures extending from the main root stems, have very thin walls which absorb water and minerals. This mineral solution is passed into the vascular core of the root from where it is transported throughout the tree. At the tip of the root, there exists a protective structure called the root cap. These loose cells are shed as the root grows into the soil.
Different trees have slightly different root systems. Some trees, such as the pine, have a strong central root called the taproot. This is usually larger than any other roots and often extends deep into the ground. Because substantial damage to this root can be fatal to the tree, trees with taproots are generally difficult to transplant.
Other trees, such as the elm or maple, do not have a dominant taproot. Their root systems are characterized by a large number of roots often closer to the surface.
The Bark
The bark is the outer protective covering of tree trunks. The form and structure of the bark can differ greatly from tree to tree. As a result, it is a useful characteristic for tree identification.
The bark is made up of two layers - outer bark and inner bark.
The outer bark is made up of dead cells. This layer is usually quite thick, but in certain trees (young birch, for example) it is very thin.
The inner bark, known as the phloem is made up of a thin layer of living cells. These cells have extremely thin walls allowing water and nutrients (in the form of sugar solutions) to pass easily throughout the tree. Somewhat akin to human skin, old bark is shed, and new bark is formed from the inside.