Spores of living organisms are amazing cells. On Earth, they can be in very low or high temperatures, high blood pressure and radiation. It is proved that disputes are even in outer space, traveling through the vast universe. What is a controversy in biology? What is the secret of these cells?
Dispute: definition in biology
Translated from the Greek language, this word means "sowing." But the presence of these cells is not unique to plants. What is a dispute? There is a clear concept in biology: these are asexual reproduction cells. With their help, the process of reproduction of their own kind is carried out by bacteria - unicellular organisms that do not have a nucleus.
Mushrooms are also capable of spore formation. Everyone saw how the bread, which has been in a plastic bag for a long time, begins to become white coated - mold fungi begin to develop on it. Over time, plaque begins to turn gray or green. This means that the fungus has already formed spores and begins to multiply. Here is another example. In a damp room, molds often settle on walls that begin to bloom. It is quite difficult to get rid of mold, because the fungus is able to spread spores over a distance of several meters.
Structure
So we figured out what a dispute is. In biology, all living objects are considered from the point of view of the relationship between the structure and the functions performed. Asexual reproduction cells come in different shapes: elliptical, oval, round. Since they are resistant to various biological factors, their surface apparatus is arranged in a special way. It consists of two shells, the space between which is filled with complex compounds of proteins with carbohydrates. To enhance protection against mechanical stresses, some spores on their surface have special formations called stiffeners.
The internal content of asexual reproduction cells is represented by the cytoplasm - the internal semi-fluid medium. It contains chromosomes and protein synthesis devices.
Plant spores
With the help of such cells, many plant organisms are able to multiply.
Plant spore is a device for propagating the very first and primitive plants. This is primarily algae. For example, unicellular chlamydomonas forms zoospores - motile cells. As a result, several identical organisms are formed from one individual at once.
The first immigrants to land, higher spore plants, are also capable of spore formation. Mosses, crowns, horsetails and ferns form special organs of asexual reproduction - sporangia. They contain asexual reproduction cells. Plants that have such organs are called sporophytes. In bryophytes, sporangia is represented by a leg with a box. When ripe, the box opens, the cells fall into the ground. In the presence of water, they germinate into the sexual generation - the gametophyte, which in mosses is represented by a green leafy "carpet". The situation is quite different for the other representatives of spore plants, which everyone is accustomed to seeing as a gametophyte - a green plant. These plants undergo a process of alternation of sexual and asexual generations.
Bacteria spores
A bacterial spore is not only a cell by which the body multiplies. When adverse conditions occur, the bacteria have to defend themselves so as not to die. It turns into a dispute in which the amount of moisture is significantly reduced, the level of intensity of all life processes decreases. When conditions change for the better, the spore throws off the membrane and an absolutely viable bacterium emerges from it. It can be concluded that for bacteria, spore formation is not a means of reproduction, but an opportunity to survive.
What is a dispute in biology has long been known. Since the appearance of the first living organisms, it was with the help of these cells that the process of reproduction took place. Of course, disputes do not ensure the recombination of genetic material, as a result of which the appearance of new useful traits becomes simply impossible. However, an exact copy and preservation of all the properties of the body spores guarantee.