How does the bacteria multiply: by spores or by division?

Bacterial organisms have long since mastered all known habitats. They are in the air, in the water, they live in other organisms. But most of all they are in the upper layers of the soil. The number of these organisms depends not only on the characteristics of the structure. It is multiplied by the great ability to reproduce. How the bacteria multiply is summarized in the article.

Who are the bacteria?

These organisms are unicellular, less often colonial organisms. They are quite primitive. The superficial apparatus is represented by a membrane and a mucous capsule, and the cytoplasm is devoid of mitochondria and plastids. Many cells have flagella, with which the bacterium can move.

Genetic material

Bacteria are prokaryotes. This means that their cells are devoid of a nucleus. But the genetic material in them is still present. The accumulations of DNA molecules are in a certain part of the cytoplasm and are called the nucleoid. In other words, we can say that prokaryotes have a core without an envelope. Therefore, they can not perform complex biochemical processes. However, this does not affect their ability to reproduce in any way.

How does the bacteria multiply?

Bacteria multiply by cell division. This is the main and fastest way. From one maternal cell, in half an hour, two daughter cells are formed. And after another period of time, two new cells are formed from the two daughter cells. This explains the large number of bacteria in nature.

Under adverse conditions, bacteria are able to form spores - cells of asexual reproduction. Occasionally, bacterial cells will bud - form small protrusions that grow, turn into adult individuals and split off from the maternal.

In what way the bacteria multiply, one can also consider the example of conjugation. This is the form of the sexual process. It is in the exchange of hereditary information between the cells. Before the beginning, the ring molecule of DNA is doubled. Further between the cells a cytoplasmic bridge is formed, according to which the hereditary information of one cell moves to another. There is an exchange of DNA. As a result, the body acquires new signs, which are often useful for it. For example, bacteria acquire resistance to the effects of adverse environmental factors, viruses or antibiotics.

Nodule bacteria live and reproduce on the roots of leguminous and cereal plants. Intruding into the root system through the affected areas or root hairs, they grow and form protrusions - nodules. Within them a favorable environment for metabolism is created. The root gives the bacteria organic substances, and bacteria - nitrogen, which is so necessary for the growth and development of plants.

Cell division in two

How the bacteria multiply depends on their species and habitat. But in two all bacterial organisms can share. This process takes place in several stages and is called binary division.

Before the beginning of division, the circular DNA molecule doubles. In other words, replication takes place. The nucleotide is divided, the daughter DNA diverges. Growing into the cytoplasm, the cell membrane is located between the DNA molecules. It is she who divides the cage and its contents in half.

A day from one cell to the light there are 72 bacterial generations. If all these bacteria remained viable, their biomass would be about 5 tons. In nature, naturally, this does not happen and most bacteria die.

Vegetative reproduction

The structure also determines how the bacteria multiply.

Colonial species and cyanobacteria (blue-green algae) are capable of vegetative reproduction. In this way, plants are most often propagated. It consists in the separation from the whole organism of its multicellular part.

Filamentous species of cyanobacteria form specialized cells, which are called heterocysts. Vegetative reproduction consists in rupturing of filaments, the boundary of which passes in the places of heterocysts.

Spherical cocci bacteria can be joined into chains, bunches or other formations. Breaking apart, they also multiply.

Spore formation

Bacteria reproduce by spores, which are formed when adverse conditions occur. Spore formation is not only a method of reproduction. Inside the spore a special environment is created, the water content decreases, the vital processes are suspended. In this state of controversy, neither high temperatures, nor ionizing radiation, nor exposure to chemicals are dangerous. When favorable conditions come again, young bacterial organisms emerge from the spores. Thus, the formation of spores is an additional opportunity to maintain the viability of cells in unsuitable conditions for life. There are cases when bacterial spores remained viable for tens or even hundreds of years.

Incubation

Another way to protect against adverse conditions and the way of reproduction is the formation of cysts. They are bubbles with thick shells. In the state of cyst bacteria can be a long time. In this case, they do not die from temperatures over 200 degrees. With the onset of normal conditions, the bacterium leaves the envelope and begins the usual binary division.

How the bacteria multiply, it is more likely to solve the environmental conditions. When there is not enough nutrients and moisture, there is an excessive oxygen content, air is too high or low, bacteria use the processes of inclusions or sporulation. In comfortable conditions, they divide or multiply vegetatively. It is this variety of ways of reproduction, to which bacteria are capable, that determines their quantity in nature. If the process of dividing one cell of a bacterium did not stop within 10 days, they could cover the entire surface of the globe.