Biologi

ROOT STRUCTURE :

In Plant Root Function

The root function in plants in general as follows.
1) As a backer rod plant
2) where the plant attached to the media (soil) because it has the ability to break through layers of soil.
3) It absorbs mineral salts and water through the root hairs.
4) In some plants, the root is used as a storage of food reserves, such as carrots and sweet potatoes.
5) In certain plants, such as mangrove species (Rhizophora sp.) Roots contribute to breathing.
6) Tool vegetative propagation in certain plants.


Type Type of Plant Roots

Based on the type, the roots of plants are divided into three types, namely type of riding root, type root fibers and the type of adventitious roots.

This type of riding is owned by root dikotil plant roots, while the type of root fibers monocot plants are owned by root. At the root type of riding consists of a large root branches and twigs with some roots. The root comes from the primary root development of germinating seeds. (This type of riding Plant Root)

While on the type of root fibers, consisting of a number of small roots, which to lean all have the same size. Rooting system of fibers formed at the time of forming the primary root of the number of branches, the branch does not become large, and the subsequent shrinking of primary roots, looks like the threads. Consider Figure 1. (This type of plant root fibers)

While the type of adventitious rooting, the roots growing from every part of the plant and not the primary root. Like roots coming out from the stem tubers, roots out of the trunk (graft). (This type of adventitious roots of plants)

Figure 2. Wild roots (adventitious)
on corn

In addition to protrude from the base of shoots, roots of plants can also exit from the ground. Roots can therefore arise from stem or leaf. We can call the root that grows in parts of this undue called wild or adventitious roots (see Figure 2.). Wild roots serve as a buffer and ancillary plants towering stems. Example is the corn plant roots that grow from the trunk.

Structure & Root Network Composer at The morphology and anatomy of plants

Morphologically (cut lengthwise) Structure and root tissue comprising: neck root (root base), stem root, branch root, root fibers, hair root, root tip and root cap (kaliptra). Consider Figure 3.

Figure 3. Roots and their parts

The roots that are directly connected to the stem is called the root neck. While the part that sits between the neck and trunk is called the root of the root tip. Furthermore, the root also has a prominent part in the rod that forms the root branch. In addition, there are also fine branching roots called root fibers. Then, the root also has a section on tissue differentiation epidermisnya experience. This part is called root hairs. Meanwhile, the root tip that serves as a protective mesistem elongated roots penetrate the soil when the hood is called the root.

Roots developed from apical meristem at the root tip is protected kaliptra (root cap). Apical meristem divide always produce new cells. New cells form on the hood or inside the root apical meristem. Cleavage of the apical meristem form the elongation region, called the zone of cell extension. Behind him there is a zone of cell differentiation and cell maturation zone. In the zone of cell differentiation, root cells develop into multiple cell permanently. For example some cells differentiated into xylem, phloem, parenchyma, and sklerenkim. Consider Figure 4.

Figure 4.
The structure of root morphology

In anatomy (cut crosswise) Structure and tissue constituent of plant roots as follows:

1) The epidermis consists of a single layer of cells arranged meeting. Thin cell walls so easily penetrated water. Have root hairs that are the result of cell activity behind the growing point. Hair root hairs serve to expand the absorption field.
2) The cortex consists of many cells and is composed berlapislapis, thin cell walls and have plenty of space between cells for gas exchange. Jaringanjaringan contained in the cortex, among others: parenchyma, kolenkim, and sklerenkim.

Figure 5.
Kaspari ribbon in endodermis cells. Tues endodermis with thickened cork is difficult to be penetrated by water.

3) Endodermis located next to the cortex. Endodermis form a compact layer of cells without intercellular spaces. Cork cell wall thickening. Rows of cells called the endodermis with thickened cork ribbon kaspari. Kaspari ribbon is not impermeable to water and other solutes. Water and solutes which pass through the protoplasm is endodermis should be attached to the ribbon kaspari and through the cell wall that is located parallel to the cylinder center. (Figure 2.13 kaspari ribbon). At the endodermis layer are also found lining the thickened substance cork. Thickening of the form letter U, so-called cell U. These cells are impermeable so that water can not be passed. Thickening of the cork can not be penetrated by water, so water must enter the cylinder through the center of endodermis cells are located in alignment with the xylem whose walls are not thickened, called the successor of the cell water. So Endodermis is a separator between the cortex to the stele and serves as a regulator of the way the solution is absorbed from the soil into the central cylinder ..
4) Stele (central cylinder) is located next to the endodermis. Beam transport are among the stele.

Compilers of the root tissue anatomy in general you can observe in Figure 6. the following.

Figure 6.
Constituent network structure of plant roots and root dikotil monocot plants were observed in the transverse.

STEM STRUCTURE :

Structures, Networking, Types & Functions of Plant Trunk - Trunk is part of the system in the plant shoots. It lies on the ground. This organ is categorized as a producer of lateral tools, such as leaves, buds, and flowers. In the trunk there are books (nodes) or the leaf is attached and a segment (internode), which is part of the stem that is located in between the books.



In addition to books and sections, there is a bud on the stem. Buds are found on the angle between the leaves and stems are called axillary buds. Shoots is likely to be a branch. As for the end of the rod there is a terminal bud. Consider Figure 1

Figure 1 Parts of the trunk

A.      Trunk Function in Plants

In general, the trunk has the following functions.
1) For the transport of water and nutrients from the roots. (Function in Plant Stem 1)
2) Expanding the plant canopy for efficient capture of sunlight. (Trunk Function in Plant 2)
3) The growth of generative organs. (Function in Plant Stem 3)
4) The efficiency of pollination and seed dispersal helps. (Function in Plant Stem 4)
5) In certain plants, as the storage of food reserves, for example in the form of tubers or rhizomes. (Function in Plant Stem 5)

B. Trunk Network Structure In Plant

In general, the network structure of plant stems compiler consists of three parts, the epidermis, cortex, and stele. The network structure of the constituent rods (from outside to inside) and their characteristics are described in the following description.

1) Plant stem epidermis
- Composed by a layer of cells, arranged a meeting, without intercellular spaces, the outer wall there is a cuticle that serves to protect the stem from the loss of water that is too big. In plants there is an old wood that has a cork cambium replaces the function of the primary network.
- Cork cambium activity is to perform gas exchange through a slit called lenticels. Epidermal derivatives such as silica cells and cork cells, such as the stems of sugar cane.
2) Plant stem cortex
- Composed by several layers of parenchyma cells that are not regular and thin-walled, plenty of space between cells.
- There kolenkim and sklerenkim that serves as an advocate and amplifier body.
- Cells of the inner cortex containing starch called floeterma (starch sheath).
3) Stele (central cylinder) Plant stem
  - The outermost layer is called perisikel.
- Inside, the parenchymal cells and transporting files.

Figure 2 Network vessel on the plant (a) monocots, and (b) dikotil.

C. The network structure outside the Trunk Plant
Differences outside the structure in higher plants can be divided into two groups, namely rods herbaceous plants and woody plant stems. Plants herbaceous and woody plants have leaves along the stem.

1) Stem herbaceous plants
Trunk usually herbaceous plants, green tissue is little or no wood, the size of the rods, and are generally relatively short. The outside of the stem consists of a thin epidermis and does not contain cork. Stomata in the epidermis contained in it so the network can pick up oxygen and release carbon dioxide. Example: The girlfriend of water, corn, spinach, beans, and sunflowers.

2) Stem wood plant
Stems hard and woody plants are generally relatively long age. Hard rod surface and in certain parts there lenticels. Lenticels in touch with the inner shaft and serves as a place of gas exchange in the stem. In young woody plants contained chlorophyll, so it can perform photosynthesis. However, if it formed a layer of cork photosynthetic capacity is lost. Cork layer formed by the cork cambium. Cambium activity causes tissue damage found in the cortex and epidermis. With the destruction of the network will lead to the ability of photosynthesis to be disappeared.