Biogeochemical Cycles:

Question

1. Carbon cycle- What are the ways that carbon dioxide is put into the atmosphere?

2. Carbon cycle-How is carbon dioxide removed from the atmosphere?

3. Carbon cycle-For each explanation, answer with photosynthesis or cellular respiration.

Releases carbon dioxide-

Takes in carbon dioxide-

Releases oxygen

Takes in oxygen-

4. Nitrogen cycle- How can atmospheric nitrogen become available for use by organisms?

5. Where are nitrogen fixing bacteria located?

6. Nitrogen cycle- How does soil nitrogen convert back into atmospheric nitrogen?

Limiting Factors:

Complete the T-chart describing density-dependent and density independent limiting factors on population growth.

Density- Dependent

Density- Independent

Make the answers short for 1-6 and make them seem like a 9th grader wrote them

Answer 1

Biogeochemical Cycles:

1. Carbon Cycle - Ways carbon dioxide is put into the atmosphere:

   • Combustion (burning fossil fuels)
   • Decomposition of organic matter
   • Cellular respiration

2. Carbon Cycle - How carbon dioxide is removed from the atmosphere:

   • Photosynthesis (by plants)
   • Absorption by the oceans

3. Carbon Cycle:

   • Releases carbon dioxide: Cellular respiration
   • Takes in carbon dioxide: Photosynthesis
   • Releases oxygen: Photosynthesis
   • Takes in oxygen: Cellular respiration

4. Nitrogen Cycle - How atmospheric nitrogen becomes available for use by organisms:

   • Nitrogen fixation by bacteria converts nitrogen gas (N₂) into ammonia (NH₃) or other compounds.

5. Where nitrogen-fixing bacteria are located:

   • They are mainly found in the soil and in root nodules of some plants, like legumes (e.g., peanuts, beans).

6. Nitrogen Cycle - How soil nitrogen converts back into atmospheric nitrogen:

   • Denitrification by bacteria converts nitrates (NO₃⁻) back into nitrogen gas (N₂), releasing it into the atmosphere.

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Limiting Factors:

Density-Dependent:

• Competition for resources
• Disease spread
• Predation
• Stress from overcrowding

Density-Independent:

• Natural disasters (like floods or wildfires)
• Weather conditions (like droughts or extreme temperatures)
• Human activities (like deforestation)