Bacteria, according to scientists, are the most ancient inhabitants of the Earth. They appeared on the planet in time immemorial and for a long time were the only ones on it. Their structure is primitive. These are unicellular organisms, many of which still retain the basic features of their ancestors, who populated the Earth in ancient times. The importance of bacteria in nature and human life is even difficult to objectively evaluate.
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Since the invention of the first powerful microscope (17th century), allowing to examine these small inhabitants of the sea and land, many have been discovered. In science, they were singled out in a separate group, which is called “bacteria”. Before talking about the importance of bacteria in nature and human life, a few words about themselves.
A bit about bacteria
They can have a different shape. Cocci are spherical, bacilli are rod-shaped, vibrios are like commas, spirillas are spiral, streptococci are chain, staphylococci are clusters, diplococci are rounded paired. All of them are able to move with the help of flagella or in other ways. Bacteria are found everywhere: even in drops of the purest water, in the soil, in the air, on stones and on the surface of the skin. They are also found inside some other organisms, for example, in humans. Millions of bacteria can live in just one gram of chernozem. They are unpretentious and extremely viable: they withstand heat up to 90 degrees, do not die when frozen, rise into the atmosphere up to 30 km, go down into the soil for kilometers, live in the depths of the ocean - the true masters of our planet!
The importance of bacteria in nature and human life
- Biomass conversion. Bacteria diligently process and utilize dead organisms of animals and plants. As a result, they turn into fertilizers and soil layers, supporting the circulation of biomaterial in nature. For example, the leaves that fell from the tree in the fall to the ground by the next season will be turned by bacteria into high-quality humus, fertilizing the soil, helping the tree to feed.
- Absorption and fixation of nitrogen. Only these organisms can assimilate nitrogen. Special enzymes allow bacteria to absorb nitrogen from the atmosphere and combine it with minerals, turning them into fertilizers for plants.
- Oxygen production. Most likely, without bacteria we would suffocate. Because the lion's share of oxygen for the earth’s atmosphere is produced by the myriad of these little creatures. This, perhaps, is the main significance of bacteria in nature and human life.
- Production of dairy products. Without these small organisms, there would be no sour milk, and, therefore, yoghurts, kefir, cheeses, and other products familiar to us.
- On the farm. And in agriculture, bacteria help the farmer fight pests and weeds by introducing bacterial fertilizers into the soil .
The importance of bacteria in nature and human life. Advantages and disadvantages
However, these microscopic organisms are not only our assistants. From them there is harm to nature and man. Bacteria carry some dangerous diseases: for example, cholera, tuberculosis and many others. They can cause epidemics that can destroy humanity. Even various deadly bacteriological weapons, now banned in the world, have been created. Therefore, a person needs to keep them under constant control.
These materials can be used for the lesson "The value of bacteria in nature and human life" (Grade 6).