Explore topic-wise MCQs in Microbiology.

In the process of nitrogen fixation, which of the following microorganism is involved?

An example of a symbiotic nitrogen fixer is

The transformation of nitrates to gaseous nitrogen is accomplished by microorganisms in a series of biochemical reactions. The process is known as

The groups of symbiotic bacteria, which have the ability to fix nitrogen

Nitrifying bacteria can not be isolated directly by the usual techniques employed to isolate hetrotrophic bacteria. The reasons may be due to

The phenomenon of commensalism refers to a relationship between organisms in which

The diagnostic enzyme for denitrification is

Which of the following microorganism use H₂S as the electron donor to reduce carbon dioxide?

The population of algae in soil is __________ that of either bacteria or fungi.

A heterocyst is

Nitrogen fixation refers to the direct conversion of atmospheric nitrogen gas into

The nonsymbiotic bacteria which fix nitrogen live in the soil independently are

Which of the following is not the biofertilisers producing bacteria?

Most soil protozoa are flagellates or amoebas, having their dominant mode of nitrogen as

Which of the following is capable of oxidizing sulfur to sulfates?

Denitrification may be distinguished as

The conversion of molecular nitrogen into ammonia is known as

Which of the following species of different genera of bacteria are not capable of transforming nitrate to nitrogen?

Some microorganisms have the ability to increase the nitrogen content of soils, are called as

__________ play a key role in the transformation of rock to soil.

The groups of bacteria which have the ability to fix nitrogen from air to soil are

The nitrogenase consists of

For rapid decomposition by microbes, the substrate should have a C/N ratio of

Which are the main source of biofertilisers?

The diagnostic enzyme for nitrogen-fixing organisms is

Which of the following fungi on infecting crop roots can improve their uptake of phosphorus and other nutrients?

Which of the following soil microorganism is involved in the reduction of sulfates to H₂S?

Assimilative denitrification is done by

Degree of compost maturity can be assesed by

The physical structure of soil is improved by the accumulation of

The breakdown of cattle manure in biogas is accomplished by which of the following type of bacteria?

The microbial ecosystem of soil includes

Syntrophism involves

The crops which are involved in nitrogen fixation are

Bacteria, as a group, are responsible for

The organisms responsible for the characteristic musty or earth odor of a freshly plowed field is/are