Oxygen Cycle

Q.

The percentage of oxygen present in the atmosphere is about .

Q.

How is oxygen replenished in nature?

Q. Describe oxygen cycle and the carbon cycle.

Q.

Which of the following statements is not correct?

1. Forests protect the soil from erosion.

2. Plants and animals in a forest are not dependent on one another.

3. Forests influence the climate and water cycle.

4. Soil helps forests to grow and regenerate.

Q.

Which is the gas essential for animals?

1. nitrogen

2. hydrogen

3. oxygen

4. carbon dioxide

Q.

Carbon dioxide is removed from the atmosphere by respiration.

1. True
2. False

Q.

Elemental oxygen is poisonous to which group of organisms?

1. Aerobic bacteria
2. Anaerobic bacteria
3. Aquatic organisms
4. Terrestrial organism

Q.

What are the two elemental forms of oxygen found in the atmosphere?

1. Oxygen
2. Ozone
3. Oxygen radical
4. Tetra atomic oxygen

Q. Oxygen from atmosphere is used up for processes such as:

1. photosynthesis
2. combustion
3. respiration
4. transpiration

Q. Plants containing chlorophyll convert carbon dioxide into glucose in presence of ___.

Q.

The process in which oxygen is released into atmosphere is:

1. Green house

2. Photosynthesis

3. Combustion

4. carbon cycle

Q. Which of these processes helps in nitrogen fixation?

1. Combustion
2. Transpiration
3. Lightning
4. Respiration

Q.

" All plants give out O₂ during day and CO₂ during night", what is wrong with this statement?

Q.

Mention the significance of oxygen.

Q. Why does the percentage of gases like oxygen, nitrogen and carbon dioxide remain almost the same in the atmosphere?

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

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

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

1. Oxide formation
2. Combustion
3. Photosynthesis
4. Respiration

Q.

Elemental oxygen is poisonous to which group of organisms?

1. Aerobic bacteria
2. Anaerobic bacteria
3. Aquatic organisms
4. Terrestrial organism

Q.

How is oxygen renewed in the air?

Q. List two forms of oxygen found in the atmosphere full stop name the process(s) by which: (A)oxygen from the atmosphere is used up (B) oxygen is returned to the atmosphere.

Q. ________is used by living organisms for oxidation of glucose and other organic substances in order to liberate energy.

1. Carbon dioxide
2. Oxygen
3. Nitrogen dioxide
4. Methane

Q.

The two forms of oxygen found in the atmosphere are :

1. water and ozone

2. water and oxygen

3. ozone and oxygen

4. water and carbon dioxide

Q.

What is the percentage of oxygen in the air? Name the biological process by which it is mainly returned to the atmosphere.

Q. Which among the following is/are not a form of oxygen present in the atmosphere?

1. Molecular oxygen $\left(O_2\right)$
2. Ozone $O_3$
3. Oxygen radical (O)
4. Tetra atomic oxygen $O_4$

Q.

Explain the oxygen cycle in detail.

Q.

Question 5
What are the two forms of oxygen found in the atmosphere?

Q. Which of the following is incorrect regarding the process X?


(a) It uses oxygen to liberate energy.
(b) Oxidation of glucose occurs.
(c) It releases oxygen and water.
(d) It consumes carbon dioxide and water.

1. (c) and (d)
2. (a) and (b)
3. (a) and (c)
4. (b) and (c)

Q. Ozone and oxygen are the two elemental forms of oxygen that are found in the atmosphere.

1. True
2. False

Q. Identify the given biogeochemical cycle.

1. Mineral cycle
2. Nitrogen cycle
3. Water cycle
4. Oxygen cycle

Q.

What is the percentage of carbon dioxide in our atmosphere?