Processes Involved in the Oxygen Cycle

Q. Which of the following processes add oxygen to the atmosphere?

1. Combustion
2. Respiration
3. Photosynthesis
4. Denitrification

Q.

How can we reduce greenhouse gas emissions?

Q. Which of the following processes add oxygen to the atmosphere?

1. Combustion
2. Respiration
3. Photosynthesis
4. Denitrification

Q.

Name few greenhouse gases.

Q. Which of the following process returns the oxygen back to the atmosphere?

1. Photosynthesis
2. Decomposition
3. Combustion
4. Respiration

Q. Which of the following is released when anaerobic bacteria act upon waste substances?

1. Hydrogen sulphide
2. Methane
3. Carbon dioxide
4. Water

Q. Which of the following is released when anaerobic bacteria act upon waste substances?

1. Hydrogen sulphide
2. Methane
3. Carbon dioxide
4. Water

Q. Which of the following process returns the oxygen back to the atmosphere?

1. Photosynthesis
2. Decomposition
3. Combustion
4. Respiration

Q. Which of the following is essential for the sustenance of life in aquatic animals?

1. Ozone
2. Dissolved oxygen
3. Sulphur
4. Chlorofluorocarbons

Q.

Oxygen is returned to the atmosphere mainly by ______.

1. photosynthesis

2. burning of fossil fuel

3. respiration

4. decomposition

Q. Which two forms of oxygen are found in the atmosphere and why it is essential?

[3 Marks]
[Oxygen Cycle]

Q. Oxygen cycle is most connected to which other element cycle?

1. Nitrogen cycle
2. Phosphorus cycle
3. Hydrogen cycle
4. Carbon cycle

Q. maintains oxygen composition on Earth.

1. Photosynthesis
2. Transpiration
3. Nitrification

Q. ___ is needed for sustaining the aerobic microbes when organic waste is decomposed.

1. Oxygen
2. Nitrogen
3. Carbon
4. Phosphorous

Q.
Identify the processes A and B in the image given above.

1. A-Respiration; B-Transpiration
2. A-Photosynthesis; B-Respiration
3. A-Combustion; B-Respiration
4. A-Transpiration; B-Photosynthesis

Q. Pick the processes in which oxygen is used up.

1. Respiration in humans
2. Decomposition
3. Rusting
4. Combustion
5. Photosynthesis
6. Transpiration
7. To put out fire
8. Respiration in plants