helpful bacteria and harmful bacteria

Bacteria are minute microscopic prokaryotes. They are unicellular organisms, which are usually identified by their specific activities, more than their general organisati..

show a primitive type of sexual reproduction called genetic recombination. Conjugating Bacteria In this process, the exchange of genetic materials takes place by a process called conjugation . Conjugating bacterial cells are in contact through a hollow tube called pilus. In the hig..

These are bacteria which live in a mutually beneficial association with other organisms. Such bacteria derive the essential nutrients from their host organisms and in that process help the host through some of their biological activities. 1. The most familiar example o..

Bacteria exhibit different modes of nutrition. On this basis, broadly two types of bacteria can be recognised autotrophic bacteria and heterotrophic bacteria..

These are bacteria which occur in the body of animals and plants, obtaining their organic food from there. Most of these bacteria are pathogenic , causing serious diseases in the host organisms either by exploiting them or by releasing poisonous secretions called toxi..

These are bacteria which are unable to manufacture their own organic food and hence are dependent on external source. These bacteria can be distinguished into three groups as follows: Saprophytic Bacteria: These bacteria obtain their nutritional requirements ..

These are bacteria which are able to synthesize their own organic food from inorganic substances. They use carbon dioxide for obtaining carbon and utilise hydrogen sulphide (H 2 S) or ammonia (NH 3 ) or hydrogen (H 2 ) as the source of hydrogen to reduce carbon. These bacteria c..

It is the most common mode of asexual reproduction. The cytoplasm and nucleoid of a bacterial cell divide equally into two, following replication of DNA. The cell wall and cytoplasm also split resulting in the formation of two daughter cell..

Phosphate Solubalising Bacteria - Some bacteria like Aspergillus awamori have the capacity to solubalise the phosphates fixed in soil. It must be recalled here that most of applied phosphorus is fixed in soil, and a small part of it is available to plants every year as labile ph..

One of the unsolved mysteries in biology is that of viruses. Due to the absence of a cellular organization viruses cannot be placed with either prokaryotes or eukaryotes. They are considered as intermediate between living and non-living systems. Viruses are active and show reproduction only inside ..