Plant, its parts and functions

The principal parts of a plant are: 1. the root system, 2. the stems and leaves; 3. the reproductive part made up of flowers, fruits or seeds. The root grows downward into the soil and has two main functions - to absorb plant nutrients and water from the soil and to anchor the plant. The fact is that there is more than one type of root system, hi many gymnosperms and dicots, there is typically a taproot system in which a single, large, deep growing root is accompanied by less prominent secondary roots. The taproot itself may function as a food- storing organ, as in carrots and radishes. In contrast, mono-cots and some dicots have fibrous root systems composed of numerous thin roots. Such a root system holds soil very ell, making grasses very useful on hillsides where runoff from rain could cause erosion. Fibrous root systems are for adsorption of water and minerals.

As to stems and leaves, they are usually above the ground. A stem and its leaves, taken together, are called a shoot. Unlike the root, the stem may be green and capable of photosynthesis. The stem may be regarded as a device for holding and displaying the leaves to the sun, so as to maximize the photosynthesis yields, as well as for providing transport connections between the root and leaves. The points where leaves are attached to the stem are called nodes, and the stem regions between nodes are called intermodes. Where each leaf meets the stem, there is a lateral bud, which develops into a branch. A branch is also a stem.

Each lowering plant has leaves. A typical leaf consists of a green, broad, thin portion, the blade, which contains a system of vascular tubes, called veins. In most plants, it is the leaves that carry on most photosynthesis, producing food and releasing oxygen gas. Other important metabolic processes, including a key and releasing oxygen gas. Other important metabolic processes, including a key part of nitrogen cycle, are also among the responsibilities of the leaf.

In some species, leaves are important food storage organs; in others water is stored in the leaves. Leaves are adapted to serve as photosynthetic, light-gathering organs. The leaves mybe compound as with clovers and potatoes, or simple as in the case of the poplar tree.

A flower is the part of the plant where seeds are produced. Thus to produce seeds the plant must have flowers. A complete flower is made up of four principle parts, namely a) sepals, b) petals, c) stamens, d) the pistil. A seed consist of an embryo, and one or more seed coats. The usual shapes for fruits and seeds are globular, elliptical, ovoid, conical, etc. All parts of a plant must be developed well and proportionally enough to function properly.

Answer the questions

1. What are the principle parts of a plant?

2. What are the main functions of the root system?

3. What is a taproot?

4. What is the difference between a taproot and a fibrous root system?

5. What part of a plant take part in the photosynthesis?

6. What are the main functions of the stem?

7. What blade does a typical leaf consist of?

8. What functions of leaves do you know?

9. Where are the seeds produced?

10. What are the principle parts of a complete flower?

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