Nitrogen Cycle

Q. How do biotic and abiotic factors affect each other?

Q.

What Is the Role of Bacteria in Increasing Soil Fertility?

Q. We sprinkle salt on dead animals to decompose them easily which means that microbes work better on things in which salt is added but on the other hand we we add salt to pickle to check microbial growth. How is it possible that on one hand salt doesn't allow microbial growth and on the other hand it allows microbial growth to happen

Q.

Which of the following increase the fertility of soil ?

A. Lactobacillus bacteria B. Rhizobium bacteria C. Spirogyra algae D. Blue-green algae

(a) A and B (b) B and C (c) A and D (d) B and D

Q.

What organisms are involved in the nitrogen cycle?

Q.

Draw a neat, labelled diagram of nitrogen cylcle in nature. Which natural phenomenon occurring in the sky is responsible for nitrogen fixation ?

Q.

Which bacteria help improve soil fertility?

Q.

Cells of root nodules of leguminous plants fix nitrogen.

1. True
2. False

Q.

How to make Rhizobium culture?

Q.

Name the nitrogen-fixing bateria present in root nodules of leguminous plants.

Q.

State two ways by which fixation of nitrogen occur naturally.

Q. What is decomposition?

Q.

What are the 3 uses of bacteria?

Q. Nitrogen fixation means:

1. manufacture of nitrogen
2. conversion of nitrogen into nitric acid
3. liquefication of nitrogen
4. conversion of atmospheric nitrogen into useful compounds
5. mixing of nitrogen with other elements

Q. Rhizobium helps in atmospheric _________ fixation.

1. oxygen
2. water
3. nitrogen
4. carbon dioxide

Q.

What are the disadvantages of the nitrogen cycle?

Q.

What is the importance of symbiotic relationship of nitrogen-fixing bacteria with plants and some benefits also??

Q.

State the role of bacteria in making the soil fertile.

Q.

Write the steps involved in nitrogen cycle.

Q.

The process of conversion of free atmospheric nitrogen into usable compounds is called __________

Q. Which of the organisms play an important role in the nitrogen cycle?

1. Rhizobium
2. Blue-green algae
3. Nitrosomonas
4. Tuberculosis

Q.

How is the nitrogen cycle affected by global warming?

Q.

How do microbes clean the environment

Q.

Why nitrogen cycle is called a perfect cycle?

Q.

Why do organisms require nitrogen?

Q.

Describe the nitrogen cycle with a diagram.

Q. Which of the following forms of nitrogen cannot be absorbed directly by plants?

1. NO3-
2. NO2-
3. NH3
4. N2

Q. Statement 1: Atmospheric nitrogen cannot be used up directly by the plants.

Statement 2: Rhizobium lives in a symbiotic relationship with legumes.

1. Only statement 2 is correct
2. Only statement 1 is correct
3. Both the statements are correct
4. Both the statement are incorrect

Q. ____ is the process of breaking down dead and decaying organic matter into simple substances.

1. Fermentation
2. Decomposition
3. Excretion
4. Dilution

Q.

Name one 'bilogical nitrogen-fixer'.