Cycles of Life: Carbon, Nitrogen, and Water in Our Ecosystem

The video tutorial explains the four main natural cycles: carbon, nitrogen, and water cycles. It details how carbon is cycled through photosynthesis and respiration, the role of nitrogen-fixing bacteria in the nitrogen cycle, and the phases of the water cycle, including evaporation and precipitation. Each cycle's importance in maintaining ecological balance is highlighted.

Which of the following is NOT one of the four main cycles in nature?

• Carbon cycle

• Photosynthesis

• Oxygen cycle

• Nitrogen cycle

What is the primary role of carbon in the ecosystem?

• To act as a temperature control component

• To provide energy through photosynthesis

• To form fossil fuels

• To decompose organic matter

How is carbon primarily extracted from the atmosphere?

• Through combustion

• Through decomposition

• Through photosynthesis

• Through respiration

What percentage of the atmosphere is nitrogen?

• 21%

• 78%

• 0.038%

• 50%

Which organisms are primarily responsible for fixing nitrogen from the air?

• Decomposers

• Carnivores

• Bacteria and fungi

• Herbivores

What happens to nitrogen compounds when plants and animals decompose?

• They are absorbed by the atmosphere

• They convert into nitrates

• They become fossil fuels

• They evaporate

In what forms does water exist on Earth?

• Solid and gas only

• Liquid and gas only

• Solid and liquid only

• Solid, liquid, and gas

What is the term for the amount of water vapor in the air?

• Humidity

• Condensation

• Precipitation

• Evaporation

What causes water droplets in clouds to fall to the ground?

• Wind

• Evaporation

• Gravity

• Condensation

Which of the following is NOT a source of water evaporation?

• Ponds

• Oceans

• Clothes drying

• Mountains