Grade 12 Science Quiz: Cycles in Nature

What is the process by which water is converted from liquid to vapor and released into the atmosphere?

• condensation

• sublimation

• evaporation

• precipitation

What is the term for the process by which water vapor in the atmosphere is converted into liquid water or ice crystals and falls to the Earth's surface?

• evaporation

• sublimation

• precipitation

• condensation

What is the name of the process by which ammonia is converted into nitrites and then nitrates by soil bacteria?

• Nitrification

• Ammonification

• Photosynthesis

• Denitrification

What is the term for the process by which nitrates are converted back into nitrogen gas by denitrifying bacteria?

• Denitrification

• Nitrogenation

• Nitrification

• Nitrate Reduction

What is the term for the movement of phosphorus from land into water bodies, often due to agricultural runoff?

• Urbanization

• Deforestation

• Eutrophication

• Desalination

What is the primary source of energy for the process of evaporation in the water cycle?

• Electricity

• The sun

• Wind

• The moon

What are the two main forms in which nitrogen is found in the atmosphere?

• Oxygen gas and nitrogen compounds

• Carbon dioxide and nitrogen gas

• Hydrogen gas and nitrogen oxide

• Nitrogen gas (N2) and nitrogen compounds

What is the role of phosphorus in living organisms?

• It has no role in living organisms

• It is essential for the formation of DNA, RNA, and ATP, and is also a component of cell membranes and bone structure.

• It is only used for energy storage

• It is toxic to living organisms

What are the environmental impacts of excessive phosphorus runoff into water bodies?

• Increase in biodiversity

• Promotion of healthy aquatic ecosystems

• Eutrophication, algal blooms, and oxygen depletion

• Decrease in water acidity

How does the nitrogen cycle differ from the water and phosphorus cycles in terms of the role of the atmosphere?

• The water cycle involves the conversion of water vapor in the atmosphere into a form that can be used by living organisms.

• The nitrogen cycle involves the conversion of nitrogen gas in the atmosphere into a form that can be used by living organisms.

• The phosphorus cycle involves the conversion of phosphorus gas in the atmosphere into a form that can be used by living organisms.

• The nitrogen cycle involves the conversion of carbon dioxide in the atmosphere into a form that can be used by living organisms.