What Are Gaseous Cycles

Q. Which of the following is nitrogen fixing algae

1. Azolla, Anabaena , Azotobacter
2. Nostoc, Anabaena, Oscillatoria
3. Oscillatoria, Anabaena, Azolla
4. Azolla, Nostoc, Oscillatoria

Q. The conversion of nitrate to nitrogen is called

1. ammonification
2. nitrification
3. nitrogen fixation
4. denitrification

Q. Which of the following is gaseous cycle?
(1) Sulphur cycle
(2) Carbon cycle
(3) Phosphorous cycle
(4) Nitrogen cycle

1. 1
2. 1, 2
3. 2, 4
4. 1, 3, 4

Q.

Conversion of ammonia into nitrates through Nitrosomonas is called

1. Ammonification

2. Denitrification

3. Nitrogen fixation

4. Nitrification

Q.

Give an example of a free-living nitrogen-fixing cyanobacteria.

Q.

In an ecosystem, the cycling of nutrients is known as

1. Biogeochemical cycle

2. Geochemical cycle

3. Chemical cycle

4. Geological cycle

Q.

what is the use of nitrogen in hospitals?

Q.

What type of organism carries out nitrogen fixation?

1. Bacteria

2. Protists

3. All of these

4. Fungi

Q. Statement 1 : In due course of evolution, the number of photoautotrophs increased and enormous amounts of oxygen was released in the sea and primitive atmosphere.

Statement 2 : This oxygen then reacted with methane and ammonia leading to transform them into carbon dioxide and free nitrogen.

1. Both the statements are correct
2. Statement 1 is correct and statement 2 is incorrect
3. Statement 1 is incorrecta and statement 2 is correct
4. Both the statements are incorrect

Q.

What is the fixation of nitrogen? How does the fixed nitrogen get back to the atmosphere?

Q.

Biogeochemical is non-mineral.

What does it mean???

Q. Non-Legume nitrogen fixing organisms belong to the genus

1. Rhizobium
2. Frankia
3. Clostridium
4. Azotobactor

Q.

What type of organism carries out nitrogen fixation?

1. Bacteria

2. Protists

3. Fungi

4. All of these

Q.

name the bacterium that fixes the atmospheric nitrogen in the soil?

Q.

Nitrogen fixation is a process in which nitrogen ($N_2$) in the atmosphere is converted into ammonium ${N{H}_4}^{+}$ or nitrogen dioxide ($N{O}_2$). Which of the following is/are responsible for this?

1. Atmospheric fixation by lightning

2. All of these

3. Biological fixation by microbes

4. Industrial fixation

Q. Which of the following is gaseous cycle?
(1) Sulphur cycle
(2) Carbon cycle
(3) Phosphorous cycle
(4) Nitrogen cycle

1. 1
2. 1, 2
3. 2, 4
4. 1, 3, 4

Q. How does the percentage of nitrogen in the atmosphere remains more or less constant.

1. After plants and animals die, bacteria and fungi present in the soil convert the nitrogenous wastes into nitrogenous compounds
2. Certain bacteria and blue green algae present in the soil fix nitrogen from the atmosphere and convert it into compounds of nitrogen.
3. Once nitrogen is converted into usable compounds, it can be utilised by plants from the soil through their root system
4. All of the above.

Q. For nitrogen fixation, the pigment useful is

1. Haemoglobin.
2. Nitrogenase.
3. Leghaemoglobin.
4. Myoglobin.

Q. The bacterium involved in symbiotic nitrogen fixation is ____________.

Q. If the amount of nitrogen and phosphorous cycling through an ecosystem is greatly affected by local environmental conditions, such as heavy rainfall or the removal of large numbers of plants. Select the correct statement that signifies, the amount of carbon in an ecosystem is affected by such factors.

1. Plants make their own carbon compounds through photosynthesis
2. Plants absorb large amounts of carbon from the soil
3. Bacteria in the soil absorb large amounts of carbon
4. The primary source of carbon is the atmosphere, whereas much nitrogen and phosphorous come from the soil
5. Organisms need only minute levels of carbon

Q.

What type of organism carries out nitrogen fixation?

1. Bacteria

2. Protists

3. Fungi

4. All of these

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

Q. In nitrogen cycle, which bacteria are responsible for nitrification

Q. The end product of ornithine cycle is

1. Urea
2. Uric acid
3. NH${}_3$
4. CO${}_2$

Q. Which is not a reservoir for phosphorous in phosphorous cycle?
(1) Atmosphere (2) Lithosphere (3) Hydrosphere (4) All of the above

Q. The reservoir for the gaseous type of biogeochemical cycle exists in

1. A
2. B
3. D
4. C

Q. Assertion :The process of nitrification involves the decomposition of proteins of dead plants and animals, and nitrogenous wastes like urea, uric acid, etc. of animals of ammonia. Reason: Nitrogen cycle is a sedimentary cycle.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect