Cycles of Matter in Ecosystems

The video tutorial discusses the cycles of matter, focusing on the water, carbon, and nitrogen cycles. It compares these cycles to energy flow, emphasizing that while energy flows in one direction, matter cycles through the atmosphere, geosphere, hydrosphere, and biosphere. The water cycle involves processes like evaporation, transpiration, and precipitation. The carbon cycle highlights the role of photosynthesis, respiration, and human activities in carbon exchange, with a focus on fossil fuels and climate change. The nitrogen cycle explains the importance of bacteria in converting nitrogen into usable forms for plants.

What are the four major macromolecules that life on Earth is built from?

• Carbohydrates, lipids, proteins, nucleic acids

• Carbohydrates, lipids, vitamins, minerals

• Proteins, nucleic acids, vitamins, minerals

• Lipids, carbohydrates, vitamins, nucleic acids

How does water enter the atmosphere from plants?

• Evaporation

• Condensation

• Precipitation

• Transpiration

What drives the water cycle by heating water and causing it to evaporate?

• Earth's rotation

• Wind

• Moon

• Sun

Which process in the carbon cycle involves plants taking in carbon dioxide?

• Combustion

• Respiration

• Photosynthesis

• Decomposition

What is a carbon sink?

• A volcanic eruption

• A process that releases more carbon than it absorbs

• A process that absorbs more carbon than it releases

• A type of fossil fuel

What percentage of the Earth's atmosphere is nitrogen gas?

• 21%

• 78%

• 10%

• 50%

What role do nitrogen-fixing bacteria play in the nitrogen cycle?

• They convert nitrogen gas into ammonia

• They convert ammonia into nitrogen gas

• They decompose organic matter

• They cause precipitation

What is the process called when bacteria convert nitrates back into nitrogen gas?

• Respiration

• Nitrogen fixation

• Denitrification

• Photosynthesis

Which organisms are primarily responsible for converting nitrogen into forms usable by plants?

• Insects

• Fungi

• Algae

• Bacteria

What is the main takeaway about the nitrogen cycle?

• It is driven by the sun

• It is unrelated to plant growth

• It relies heavily on bacteria

• It is a form of energy flow