All living organisms inhabiting our planet are characterized by certain criteria. First of all, it is the activity and flow of various physiological processes. Otherwise, their manifestation can be defined by such a concept as vital activity. This is a set of all processes that occur in living beings, regardless of the level of their organization. In our article, we will dwell on some of them in detail.
Life activity is the basis of the existence of organisms
The mechanisms of physiological processes and their level are determined by the structural features of various organisms. For example, human life is very complex and subject to nervous and humoral regulation. And in viruses, it comes down to a primitive process of reproduction by self-assembly. Photosynthesis of plants, digestion of animals, cell division of bacteria - nothing more than life. This is a set of processes that provide metabolism and homeostasis.
Life processes
Aliveorganisms are characterized by such processes as nutrition, respiration, movement, reproduction, growth, development, heredity, variability and adaptation. Vitality is a combination of all of the above. Each systematic group has its own characteristics. Let's look at some of them in more detail.
Food
Depending on the type of nutrition, all organisms are divided into auto- and heterotrophs. The first group includes plants and some types of bacteria. They are able to independently produce organic substances. For this, plants use solar energy, due to which glucose monosaccharide is synthesized in chloroplasts. Therefore, they are also called phototrophs. Bacteria feed on the energy of chemical bonds of organic compounds. Such unicellular organisms are also called chemotrophs.
Animals and mushrooms absorb only ready-made organic substances. They are heterotrophs. Among them, there are several groups that differ in the nature of the food source. For example, predators attack their prey and kill it, while saprotrophs consume decaying organic matter. Mixotrophs belong to a special group. Under favorable conditions, they synthesize carbohydrates on their own, and if necessary, they switch to heterotrophic nutrition. Examples of mixotrophs are green euglena, mistletoe, hornwort, volvox.
Breathing
The concept of respiration includes not only the absorption of oxygen and the release of carbon dioxidegas. During this process, the oxidation of organic substances occurs with the release of a certain amount of energy. It is "stored" in ATP molecules. As a result, organisms are provided with a reserve that they can use if necessary. In plants, respiration occurs in the mitochondria of cells, and gas exchange is provided by such elements of the integumentary tissue as stomata and lenticels. In animals, the organs that provide this process are gills or lungs.
Many prokaryotic organisms are capable of anaerobic respiration. This means that the oxidation of organic substances in them occurs without the participation of oxygen. These include nitrogen-fixing, iron and sulfur bacteria.
Reproduction
Another manifestation of vital activity is the reproduction of organisms. This process ensures the continuity of generations. Important properties of all living things are the ability to transmit traits by inheritance and acquire new ones, which guarantees their adaptation to constantly changing environmental conditions.
There are two main ways of reproduction: sexual and asexual. The first occurs with the participation of gametes. Female and male sex cells merge, giving rise to a new organism. Asexual reproduction can occur by cell division in two, sporulation, budding, or vegetatively.
Growth and development
The living conditions of any organisms also consist in the quantitative and qualitative transformations that occur during their ontogenesis. Through cell division and regeneration processesgrowth is provided. In plants and fungi, it is unlimited. This means that they increase in size throughout life. Animals grow only for a certain period. After that, this process is terminated. Growth is accompanied by development. This concept represents qualitative changes that manifest themselves in the form of a complication of life processes. Growth and development accompany each other and are inextricably linked.
So, the vital activity of organisms is a set of physiological processes aimed at ensuring metabolism and homeostasis - maintaining the constancy of the internal environment. The main ones are nutrition, respiration, reproduction, movement, growth and development.
