Lesson the common seed bearing plant such as a grass consists of four major parts: root, stem, leaf and 4 flower. The Root

LESSON 31



The common seed bearing plant such as a grass consists of four major parts:
1) root, 2) stem, 3) leaf and 4) flower.
The Root. The roots of plants serve several purposes. The primary purpose of the root is to provide a means where by the plan t can absorb water and nutrients from the soil. The fine root hairs lie in close contact with the soil particles and under favorable conditions water and plant nutrients pass through the semipermeable membrane of the plant cell to be transported to the leaf where they enter into most interesting factory, where the raw materials of nature are elaborated into food stuffs for human and animal nutrition. The root also serves as an anchor or support for the plant. In many instances the root is an important storage organ. This may serve to carry the plant through an unfavorable environmental period such as winter.
The Stem. The plant stem, which differs greatly in the various species, serves as a connection between root and leaf. Frequently, the stem is so intimately associated with the leaf that it is difficult to differentiate them.
The stem supports the leaves and flower parts of most plants and aids in getting up into the sunlight. As a passageway for water and minerals to the leaf for manufacture of organic materials, and the transport of these manufactured products to other parts of the plant, the stem has a most important function. The stem, like
the root, may serve as a most important store house of energy.
The Leaf. Frequently it is difficult to differentiate between leaf and steam. In many respects they are alike. Particularly in the early stages of development it would require a careful examination to separate the two tissues. The leaf may be considered as serving two major functions: 1) it is the factory of the plant, 2) it is a source of nutritive materials.
While leaves vary greatly in size, shape, and structure, the typical leaf is essentially a broad thin structure which is formed on the plant as to give its upper surface the maximum exposure to light. The inner part of the leaf consists of chlorophyll – bearing cells which are capable of food manufacture. An examination of a leaf will disclose ribs or veins which aid in holding the leaf rigid. These veins form the seat of the fibro vascular system and form a direct passage from the leaf to all parts of the plant.
Scattered over the surface of the leaf are numerous small openings known as stomata. Each microscopic opening enables the carbon dioxide of the atmosphere to enter the leaf where it is dissolved in water that has been transported from the root. Green bodies known as chloroplasts are specialized structure through which the energy of the sun is brought to man.
GLOSSARY
1. chloroplast – хлоропласт;
2. bindweed – печакўт;
3. conspicuous – кўзгакўринган, сезиларли;
4. inconspicuous – сезилмайдиган, кўзгаташланмайдиган;
5. stamen – чангчи (ўсимликгулида);
6. anther –чангдон;
7. stalk –тана, поя, банд;
8. self – pollinated-ўзичангланувчи;
9. filament –тола,чўғланмалампатоласи;
10. ovary –тухумдон, тугунча, уруғдон;
11. ovule –уруғланиш;
12. stigma –бот. тумшуқча, оғизча;
13. tassel –попук, гажим;
14. silk –ипак;
15. breed –боқмоқ, кўпайтирмоқ;