Steps Involved in the Nitrogen Cycle

Q.

Explain Nitrogen cycle.

Q.

Nitrogen cannot be used by plants directly.

1. True

2. False

Q.

Are cyanobacteria nitrogen-fixing?

Q.

Nitrogen fixing bacteria use oxygen for nitrogen fixation.

1. True

2. False

Q.

What is an algal bloom and what causes it?

Q. The Nitrogen Cycle involves which of the following steps?

1. Nitrogen fixation
2. Nitrogen assimilation
3. Ammonification
4. Centrifugation

Q.

Percentage of nitrogen and oxygen in the air is ____ respectively.

1. 70% and 30% approx

2. 80% and 20% approx

3. 78% and 21% approx

4. 60% and 40% approx

Q. Which of the following statements describe the process of ammonification in nitrogen cycle?

1. Conversion of inert form of nitrogen into it's organic form.
2. Formation of nitrates from ammonia.
3. Formation of ammonia from nitrates.
4. Release of free nitrogen back into the atmosphere.

Q. Nitrogen is returned back to the atmosphere through ____.

1. nitrogen fixation
2. ammonifictaion
3. assimilation
4. denitrification

Q.

Nitrogen fixation takes place in presence of oxygen.

1. True

2. False

Q. Which of the following statements is true?

1. The process of nitrogen fixation by bacteria does not require oxygen.
2. The process of nitrogen fixation by bacteria requires oxygen.
3. None of the above.
4. Presence or absence of oxygen doesn't affect the process of nitrogen fixation.

Q. Which of the following organisms that is involved in nitrogen fixation is free living?

1. Rhizobium
2. Nitrosomonas
3. Phytoplankton
4. Algae

Q. How do nitrogen fixing bacteria contribute to the nitrogen cycle?​

1. They decompose and return nitrogen to autotrophs.​
2. They return nitrogen to the atmosphere.​
3. They convert ammonium to nitrate.​
4. They convert nitrogen to ammonium.​

Q.

The natural process of oxidation of ammonia to nitrite is known as _____________ .

1. Oxification

2. Ammoniation

3. Nitrification

4. None of the above

Q.

State the percentage of nitrogen, oxygen, and carbon dioxide in ordinary air and boiled-off air from water.

Q.

1. Why is nitrogen important for all living beings?
2. What is nitrogen fixation?

Q. Accumulation of ___ results in the formation of algal bloom in water bodies.

1. carbon
2. oxygen
3. phosphorous
4. nitrogen

Q. Which of the following bacteria is involved in ammonification?

1. Pseudomonas
2. Rhizobium
3. Nitrobacter
4. Thiobacillus

Q. The biological oxidation of ammonia to nitrite is known as:

1. Denitrification
2. Nitrogen fixation
3. Ammonification
4. Nitrification

Q. The biological oxidation of ammonia to nitrite is known as:

1. Denitrification
2. Nitrogen fixation
3. Ammonification
4. Nitrification

Q. Statement 1: Algal bloom occurs when nitrogen content increases in the water body.
Statement 2: Certain human activities lead to an increase in nitrogen content.

1. Statement 1 is false but statement 2 is true.
2. Statement 1 is true but statement 2 is false.
3. Both the statements are true.
4. Both the statements are false.

Q. Among the following, which one is recently discovered non-legume nitrogen-fixing bacterium?

1. Azotobacter paspali
2. Rhizobium
3. Nitrosomonas
4. Spirillum

Q. Which of the following processes cause nitrogen in organic matter re-enter the soil?

1. Denitrification
2. Assimilation
3. Ammonification
4. Nitrogen fixation

Q. Solid nitrate is converted back into gaseous nitrogen via___ process.

1. ammonification
2. assimilation
3. denitrification
4. nitrification

Q. Which of the following products are released when the decomposers decompose the dead plants and animals?

1. Nitrogen
2. Ammonia
3. Oxygen
4. Ozone

Q.

Rhizobium fixes nitrogen by _______________________________ .

1. Converting gaseous nitrogen to ammonia
2. Converting gaseous nitrogen to nitrite
3. Converting gaseous nitrogen to nitrate
4. None of the above

Q. Question 6
The process of nitrogen-fixation by bacteria does not take place in the presence of

(a) molecular form of hydrogen
(b) elemental form of oxygen
(c) water
(d) elemental form of nitrogen

Q. Rhizobium can be found in the root nodules of which of the following plants?

1. Carrot
2. Soybean
3. Pea
4. Sweet potato

Q. Which of the following statements is true?

1. The process of nitrogen fixation by bacteria does not require oxygen.
2. The process of nitrogen fixation by bacteria requires oxygen.
3. Presence or absence of oxygen doesn't affect the process of nitrogen fixation.
4. None of the above.

Q. Which enzymes has molybdenum as a component?

1. Succinate dehydrogenase
2. Nitrogenase
3. RUBISCO
4. PEP carboxylase