Having studied our article, you can easily fill out the root modification table . This underground organ of plants is widely used by humans in economic activities. But sometimes we don’t even guess which metamorphoses we are dealing with.
Types of Roots
The roots are the underground part of the plant. In their structure most often there are several parts. The main root develops from the root of the embryo. It is pronounced and the plant is always alone. On the main root, the lateral ones develop. They are numerous and make the process of absorption of water from the soil more intense. Roots that grow directly from the stem are called subordinate. They can also develop lateral.
Types of Root Systems
In plants, only one type of root is never formed. This would not be enough to provide mineral nutrition. The totality of the roots of one plant is called the root system.
In dandelion, it is formed by the main root, which penetrates deep into the soil, and lateral. This root system is called the core. It is characteristic of all dicotyledonous plants.
Wheat has a lot of roots. All of them are almost the same length and grow in a bunch from the shoot. Such a root system is called fibrous. Its presence is a systematic sign of monocotyledons.
Why does the root form modifications?
Remember the modifications of the roots in the biology tables (Grade 6)? These are carrots, beets, radishes ... Are these the roots? It turns out yes. The root performs vital functions in the plant. It provides its mineral nutrition, firmly holds in the soil, provides vegetative propagation. But to perform the additional functions of its usual structure is not enough. Therefore, root modifications are formed.
Root modifications: table
Types of metamorphoses of the underground organ differ in perennial and perennial plants, depending on the place of growth, climate characteristics, location relative to the support. The structure and functions of root modifications are presented in the table.
| Root Modification | Structural features | Function | Example |
| Roots | Thickening of the main root and lower sections of the stem | Stock of water and organic nutrients | Carrots, beetroot, rutabaga |
| Root tubers | Thickening of the lateral and adnexal roots | Stocking, vegetative propagation | Dahlia, chistyak, sweet potato (sweet potato) |
| Trailer Roots | Modification of the subordinate roots | Attachment to the support | Ivy |
Respiratory (air) | Lateral roots that grow up and rise above the surface of the soil or water | Water absorption from air | Orchid |
| Supporting | The adnexal roots that develop on the visible part of the stem | Hold the plant upright | Corn, Ficus Banyan |
| Sucker roots | The adnexal roots, which are able to penetrate the stems of other species | They lead a parasitic lifestyle, eating juices "neighbors" | Dodder |
Comparative characteristics of root modifications
Root crops and root tubers provide plants with the necessary nutrition in an unfavorable period. Such root modifications ( examples of plants are given in the table ) are formed exclusively in biennial and perennial species. In the first year of development, only vegetative organs are formed from their seeds. In autumn, the stem and leaves die off, and the underground part hibernates due to the supply of water and substances. The following year, such plants bear fruit and form seeds. It is the modifications of the roots that help them survive the cold winter.
The difference in root systems and growing conditions provides a variety of metamorphoses. So, respiratory roots are formed in plants that grow on waterlogged soils. Since the oxygen content in them is limited, the additional roots absorb this gas directly from the air. This makes the breathing process possible.
A plant can grow only under conditions of intense photosynthesis. Sometimes this requires location even on absolutely vertical surfaces. For example, ivy can grow even on the walls of houses.
Value in the economy and nature
Many plant names from the root modification table are familiar to everyone. First of all, these are root crops. A person uses them as food as the main food and seasoning. These are radishes, parsnips, beets, carrots, parsley, horseradish. Turnip and turnip are used as pet food. And sugar beets are a popular raw material for the food industry. Root tubers or cones have accessory kidneys. Therefore, with their help, vegetative propagation is carried out. These two types of modifications belong to the group of storage roots.
A special group of metamorphoses is made up of haustoria or sucker roots. If their cells are completely devoid of chloroplasts, such plants are parasites. They exist due to other species. One of the striking examples of parasitic plants is rafflesia, which has the largest flower. This species receives nutrients exclusively from the numerous vines of the rainforest. But the mistletoe, despite the fact that it feeds on the juices of the host, has not lost the ability to photosynthesis. Such species are called semi-parasites.
So, modifications of the root, the underground organ of plants, are formed to perform additional functions. Root crops and tubers (cones) store substances. Gaustoria provide parasitic nutrition for plants, while airborne ones carry out the process of respiration. Supporting and catching roots provide the most advantageous location of the shoot in relation to sunlight. This makes photosynthesis as intense as possible. We hope that now everyone can fill out the root modification table.