Microbes in Soil

Q. Some plants have nitrogen-fixing bacteria in their root nodules. What are these bacteria called?

1. Nitrosomonas
2. Blue green algae
3. Rhizobium
4. Azatobacter

Q. Why rhizobium bacterium attaches only to the roots of leguminous plants and not to other plants?

Q.

Which ratio is higher in ureides?

Q.

Why is Bacillus subtilis used in concrete?

Q.

Explain the significance of root nodule in leguminous plants

Q. Explain the uses and the harmful effects of micro-organisms.

Q. shows symbiotic relationship with bean plants.

1. $Rhizobium$
2. $Salmonella$ $typhi$
3. $Vibrio$ $cholerae$

Q. Identify the given images and give a suitable title.

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Q. Identify the given images and give a suitable title.

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Q. The bacteria in the root nodules of leguminous plants convert atmospheric _______ into its compounds.

1. oxygen
2. nitrogen
3. sulphur
4. sodium

Q. Which one of the following shows symbiotic relationship with bean plants?

1. Lactobacillus
2. Saccharomyces
3. Clostridium
4. Rhizobium

Q. The dead remains of plants and animals are the major source of nutrition for _______.

1. decomposers
2. heterotrophs
3. producers
4. autotrophs

Q. Conversion of free nitrogen into it's compounds is called .

1. nitrogen fixation
2. nitrification
3. assimilation

Q. Plants utilise nitrogen in the form of for growth.

1. nitrous oxide
2. nitrogen dioxide
3. nitrate ions
4. nitric acid

Q. is a process in which nitrates are converted back into nitrogen gas.

1. Nitrification
2. Denitrification
3. Ammonification