1.5 Biogeochemical Cycles

• Biogeochemical cycles are the natural pathways through which essential elements and chemical compounds move between the biotic and abiotic components of an ecosystem
• The carbon cycle ensures that carbon remains available to support the growth of living organisms and helps regulate global climate.
• What are biotic components in biogeochemical cycles?

  Living organisms
• Match the component type with its key roles in biogeochemical cycles:

  Biotic ↔️ Photosynthesis, respiration, decomposition

  Abiotic ↔️ Storage, transport, chemical reactions
• Arrange the following biogeochemical cycles from their primary focus on carbon, nitrogen, water, and phosphorus:

  1️⃣ Carbon Cycle

  2️⃣ Nitrogen Cycle

  3️⃣ Water Cycle

  4️⃣ Phosphorus Cycle
• Key processes in biogeochemical cycles include photosynthesis, respiration, decomposition, and nutrient uptake
• The carbon cycle, nitrogen cycle, and water cycle are major biogeochemical cycles.
• Arrange the key processes of the water cycle in their correct order:

  1️⃣ Evaporation

  2️⃣ Condensation

  3️⃣ Precipitation

  4️⃣ Transpiration

  5️⃣ Runoff
• What is the process called when water changes from a liquid to a gas and rises into the atmosphere?

  Evaporation
• Water vapor in the atmosphere cools and turns back into liquid water during the process of condensation
• Precipitation includes rain, snow, sleet, and hail.
• What is the process by which plants release water vapor into the atmosphere through their leaves?

  Transpiration
• Water flowing over the land surface and returning to rivers, lakes, and oceans is called runoff
• Match the process with its description:

  Evaporation ↔️ Water changes to vapor

  Condensation ↔️ Water vapor forms clouds

  Precipitation ↔️ Water falls from clouds

  Transpiration ↔️ Water is released from plants
• The water cycle is essential for distributing water across the planet and regulating weather patterns.
• What is the natural process called by which carbon compounds move between the atmosphere, plants, soil, and fossil fuels?

  Carbon cycle
• During photosynthesis, plants absorb carbon dioxide from the atmosphere to produce glucose
• Order the key processes of the carbon cycle:

  1️⃣ Photosynthesis

  2️⃣ Respiration

  3️⃣ Decomposition

  4️⃣ Combustion
• What releases carbon back into the atmosphere and soil during decomposition?

  Decomposers
• Burning fossil fuels releases carbon dioxide into the atmosphere
• Match the carbon cycle process with its key components:

  Photosynthesis ↔️ Atmosphere, plants

  Respiration ↔️ Plants, animals

  Decomposition ↔️ Soil, decomposers

  Combustion ↔️ Atmosphere, fossil fuels
• The main reservoirs of carbon are the atmosphere, plants, soil, and fossil fuels.
• What is the natural process called by which nitrogen compounds move between the atmosphere, soil, water, and living organisms?

  Nitrogen cycle
• Nitrogen fixation converts atmospheric nitrogen gas into ammonia
• Nitrification converts ammonia into nitrite and then nitrate.
• What do plants absorb during assimilation in the nitrogen cycle?

  Nitrate or ammonium
• Denitrification converts nitrate back into atmospheric nitrogen
• Match the nitrogen cycle process with its description:

  Nitrogen Fixation ↔️ $N_{2}$ to $NH_{3}$

  Nitrification ↔️ $NH_{3}$ to $NO_{3}^{ - }$

  Assimilation ↔️ Plants absorb $NO_{3}^{ - }$

  Denitrification ↔️ $NO_{3}^{ - }$ to $N_{2}$
• Which plants host nitrogen-fixing bacteria in their root nodules, enriching the soil with ammonia?

  Legumes
• Legumes such as soybeans enrich the soil with ammonia
• Biogeochemical cycles are crucial for maintaining ecological balance by ensuring the availability of essential elements.
• Order the key processes in biogeochemical cycles:

  1️⃣ Photosynthesis

  2️⃣ Respiration

  3️⃣ Decomposition

  4️⃣ Nutrient uptake
• Match the biogeochemical cycle with its key process:

  Carbon ↔️ Photosynthesis, respiration

  Nitrogen ↔️ Nitrogen fixation, nitrification

  Water ↔️ Evaporation, condensation
• What are the living organisms in an ecosystem called that play a crucial role in biogeochemical cycles?

  Biotic components
• Non-living parts of an ecosystem, such as the atmosphere, soil, and water, are called abiotic
• Abiotic components store and transport essential elements in biogeochemical cycles.
• Match the component type with its role:

  Biotic ↔️ Photosynthesis, respiration

  Abiotic ↔️ Storage, transport
• What is another name for the water cycle?

  Hydrological cycle
• Water changes from liquid to gas due to heat during the process of evaporation
• Order the key processes of the water cycle:

  1️⃣ Evaporation

  2️⃣ Condensation

  3️⃣ Precipitation

  4️⃣ Transpiration