In nature, there are several ways to propagate plant organisms. Most of them are associated with the formation of specialized cells: spores or gametes. When the latter merge, a seed is formed in some groups of plants. What is the difference from a dispute and how is it arranged? To these and many other questions, modern science already knows the answers. Let's figure it out and we.
Spores and seeds: a matter of evolution
Life arose in water. Many representatives of algae survived in difficult conditions precisely because of the ability to form motile cells of asexual reproduction - zoospores. Consequently, the difference between the seed and the spore can be traced in the time frame.
The first immigrants to land were higher spore plants. Mosses, crowns, horsetails and ferns are spread by spores - asexual reproduction cells. Unlike the lower plants - algae, they appeared real tissue. Therefore, this group of organisms received such a characteristic name.
Further, in the process of evolution, seed plants appeared in nature. Seed is formed as a result of fusion of germ cells - gametes. This group includes gymnosperms conifers and angiosperms flowering, which occupy a dominant position in the modern plant world.
The value of spore formation
Spores can form not only plants. Bacteria (unicellular prokaryotic organisms) also multiply with the participation of spores. In addition, with the help of asexual reproduction cells, they can easily survive adverse conditions. Due to this, bacteria remain viable when exposed to high or low temperatures, ionizing radiation.
Mushrooms are also capable of spore formation. Moreover, some mold representatives of this kingdom of wildlife can throw them at a distance of more than a meter.
Intergenerational
How the life cycle occurs in spore plants can be considered on the example of mossy. The green carpet of these plants is called gametophyte, or the sexual generation. In its special organs, germ cells are formed. But when they merge, no seed is formed. How is it different from gamete spores? These are germ cells, from which a representative of the asexual generation is formed - sporophyte. In mosses, it is a dry leg with a box inside which spores mature. Once in the ground, asexual reproduction cells germinate, again forming a green gametophyte. And so it is repeated again.
Seed structure
In seed plants, when male and female gametes merge, a gene of reproductive organ is formed - the seed. Unlike spores, it has an embryo (the prototype of the future plant). Its components are the germinal root, stem and kidney. For the development of a future plant, the embryo is surrounded by a reserve of nutrients called endosperm, and is additionally protected by the seed coat. A true double cocoon against adverse environmental conditions!
Gymnosperm seeds are located on the scales of cones openly. But angiosperms form additional protection in the form of fruits.
How seeds differ from spores
Spores are single cells. They can differ in size, shape, have flagella for movement. But they have one function - providing asexual reproduction of organisms.
The more progressive part of the plant is the seed. How is this education different from the debate ? First of all, by the fact that it is an organ consisting of tissues and specialized cells.
Water is necessary for the development and germination of spores, and seeds already have such a supply in the endosperm. No wonder mosses and ferns live only in moist places.
In most plants, the seeds are inside the fruit. They are a device for additional protection and distribution of seeds. For example, the string and burdock have special trailers that are easily attached to animal hair. Ash-tree lionfish is carried by the wind, and the henboll itself scatters seeds at a decent distance.
Spore cells germinate only under certain conditions. If moisture, light or heat is not enough, they die. Seeds, due to the supply of necessary substances, can wait out adverse factors. And with the advent of the right time to give rise to a new organism.
Another bonus of seeds is their ability to acquire new traits enshrined in the genotype. This is due to the fact that as a result of the fusion of germ cells, a new combination of genetic material arises. Using this property, breeders create seeds with valuable qualities. Everyone knows winter wheat, which grows only in the cold and allows you to get a grain crop year-round.
Seed and Spore Plants
In the modern plant world, seed plants dominate, being the pinnacle of the evolutionary process. If we talk about species diversity, then only algae, bryophytes, plaids, horsetail and ferns reproduce by spores. All other plants on the planet are seed. Spruce and apricot, oak and cherry, roses and lilies ... All the plants can not be listed.
The stock of substances, the embryo of the future plant organism, additional protection, the ability to spread - all these characteristics are possessed by the seed, which differs from spores, giving its owners a number of important advantages.