Generative body. Which organ of the plant is generative?

Each plant organ has its own structural features that fully correspond to the functions performed. So, the sheet provides photosynthesis, and the root - soil nutrition. The plant is a flower, from which a fruit with seeds is formed. In this article we will consider the features of their physiology and the role in the life of plants.

What is the body

The organ can be called only the structural unit of the plant, which is formed by several types of tissues. For example, the root consists of a conductive, mechanical, educational and integumentary species. But the rhizoids of algae only in appearance look like underground organs. In fact, they consist of a set of separate cells, connected only anatomically. Therefore, this structure can not be considered by the body.

Consider the structure of higher angiosperms. Their underground body, as already mentioned, is the root. On the surface there is an escape. It consists of the axial part - the stem, and the side - sheet. In the process of growth, a flower is formed on the shoot, from which the fetus develops.

Types of plant organs

Plant organs are classified according to different signs. On the functions performed, vegetative and generative are distinguished. The first group includes the root and the escape. First of all, they carry out vegetative reproduction, which is possible due to the cleavage of the multicellular part from the whole organism. It can be carried out by root offsprings, tubers, cuttings, leaves, bulbs. The vegetative organs perform other functions in the plant. This is photosynthesis, soil nutrition, growth, carrying water and minerals.

The plant is required for the plant to perform sexual reproduction. This type of reproduction of their kind has an important advantage. Only during sexual reproduction is the recombination of genetic material, as a result of which new, often useful, signs appear. Due to this, the plant organism has the ability to adapt to new conditions of existence.

Which organ of the plant is generative

In the process of sexual reproduction, gametes participate. These specialized cells are located in the organs, which are called generative. A plant has a flower. In the course of its development, a fruit is formed, in which the seeds ripen. Such a generative organ is not available for all plants capable of sexual reproduction. For example, unicellular algae under adverse conditions are capable of forming gametes. They go out into the water and merge in pairs. As a result, a zygote is formed. It is covered with a thick shell and in this condition it suffers freezing and drying. When again favorable conditions come, the content of the zygote is divided into four motile spores.

In higher spore plants, the sex cells mature in specialized organs, which are called gametangia. In mosses they are located on the apex of the stem and have the form of oval formations. And ferns have male and female gametophytes formed on one plant - sprouting. Eggs and spermatozoa mature at different times, so the process of their fusion occurs between different plants. All spore plants need water for fertilization. This feature is the hallmark of this systematic unit, which "inherited them" from algae.

The structure of the flower

The generative organ of seed plants, which is represented by a flower, has the most perfect structure. Its main parts are the pestle, in which the egg is located, and the stamen containing spermatozoa. When they merge, the embryo of the future organism is formed.

A flower is called a shortened and limited modified growth . In addition to the stamen and pistil, it includes a pedicel and perianth. The first part is an elongated extension of the stem. In nature, shortened and barely noticeable pedicels are often found. Examples of such plants are corn, sunflower, plantain, clover. Similar structures are called sedentary.

The perianth includes a calyx consisting of a set of carpels, and a corolla. The latter is formed by petals, which are mutated leaves. Many plants have a large and bright corolla. Roses, tulips, chrysanthemums, lilies - all these flowers have long become an excellent ornament of any holiday precisely because of this sign. Such flowers attract insects. Wind-pollinated plants have nondescript corollas and form inflorescences.

The essence of double fertilization

The process of fusion of gametes is preceded by pollination. This is the process of transferring pollen from the anther of the stamen to the stigma of the pistil. It is carried out with the help of wind, insects, water or man. In the course of fertilization, two sperm are involved. Dropping with the help of the germ tube into the pestle's ovary, one of them merges with the egg, and the other - with the central embryo. Therefore, this process in flowering plants is called double.

Types of fruits

As a result of the fusion of gametes, a modified generative organ, the fetus, is formed. It consists of a seed surrounded by shells. They are called pericarp. It can be dry and juicy. Examples of the first group are apple, drupe, berry and tykvina. But a bean, a pod, a box, a seed, a seed and a nut are dry fruits.

Seed and its biological significance

The seed belongs to the generative organ of the flowering plant. This unique structure first appears in coniferous plants. At this stage, seed plants occupy a dominant position on the planet. The thing is that in comparison with the seed, they have more progressive features of the structure. This is primarily the availability of reserve nutrients and seed shells, which reliably protect the embryo from moisture and temperature differences provided by the pericarp.

So, the generative organ of angiosperms is a flower, as a result of the development of which fruits and seeds are formed. These structures provide the process of sexual reproduction of plants and the emergence of new progressive features of the structure of organisms.