The importance of bacteria in nature and human life. Materials for the lesson in Grade 6

Bacteria, according to scientists, are the oldest 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 settled the Earth in ancient times. The importance of bacteria in nature and human life is even difficult to assess objectively.

A bunch of

Since the invention of the first powerful microscope (17 century), allowing to consider these small inhabitants of the sea and land, they were discovered many. In science they were separated into a separate group, which is called "bacteria". Before talking about the importance of bacteria in nature and human life, a few words about them.

A bit about bacteria

They can have different shapes. Kokki - spherical, bacillus - rod-like, vibrios - as commas, spirilla - spiral, streptococci - chain, staphylococcus - bunches, diplococci - 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 cleanest water, in the soil, in the air, on the stones and skin surface. They are also found inside some other organisms, for example, in humans. Only one gram of chernozem can live millions of bacteria. They are unpretentious and extremely viable: they can withstand heating up to 90 degrees, they do not die when freezing, they rise to the atmosphere up to 30 km, fall deep into the soil for kilometers, live in the depths of the ocean - the real masters of our planet!

The importance of bacteria in nature and human life

1. Conversion of biomass. Bacteria work hard to recycle and utilize dead animals and plants. As a result, they become fertilizers and soil layers, supporting the circulation of biomaterial in nature. For example, leaves fallen from a tree in autumn on the ground, by the next season will be turned by bacteria into a quality humus, fertilizing the soil, helping the tree to feed.
2. Absorption and fixation of nitrogen. Only these organisms are able to assimilate nitrogen. Special enzymes allow bacteria to assimilate nitrogen from the atmosphere and combine it with minerals, turning them into fertilizers for plants.
3. Production of oxygen. Most likely, without bacteria, we would suffocate with you. Because the lion's share of oxygen for the earth's atmosphere is produced by a myriad of these small creatures. In this, perhaps, the main importance of bacteria in nature and human life.
4. Manufacture of fermented milk products. Without these small organisms, there would not be sour milk, and, hence, yoghurts, kefir, cheeses and other products familiar to us.
5. On the farm. And in agriculture, bacteria help a farmer to fight pests and weeds with the introduction of 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 for nature and man. Bacteria carry some dangerous diseases: for example, cholera, tuberculosis and many others. They are capable of causing epidemics that can destroy humanity. Even different deadly bacteriological weapons, now banned in the world, have been created. Therefore, it is necessary for a person to keep them under constant control.

These materials can be used for the lesson "The Importance of Bacteria in Nature and Human Life" (Grade 6).