Energy flow is one-wayEnergy input from sun  autotrophs  heterotrophsEnergy is transformed from one form to anotherLight energy  heat energyLight energy  chemical energy  heat energyAmount of waterAmount of sunlightAvailability of nutrientsAppropriate temperatures.Key stone species— A species whose absence would create significant change in a community.This species would soon be replaced by another creating a very significant change in the ecosystem they live in.BIO 101 1st EditionFinal Exam Study Guide Chapter: 12Chapter 121. If the Earth has a finite amount of carbon atoms, how is it possible that there has been an increase in carbon dioxide in the atmosphere?- Its just the rearranging of atoms. 2. What is the relationship between the carbon cycle and the food web?- When plants and animals die, their bodies, wood and leaves decay bringing the carbon into the ground. Some become buried miles underground and will become fossil fuels in millions and millions of years.3. Why can’t animals take in nitrogen directly from the atmosphere to meet their nutritional needs?- It has to undergo nitrogen fixation first.4. How does atmospheric nitrogen become available for plants to use?- It has to undergo nitrogen fixation, a process whereby soil bacteria convert N2 to compounds that plants can take up, such as nitrates and ammonium. Then the plants can absorb the nitrogen.5. Why are big, fierce animals rare?- They take more accommodations to live than the smaller animals. - If there were a lot of fierce animals, they would continuously fight for the top dog position. One species would prevail, or they would divide the land and not cross the barrier.6. Why is energy transfer from one trophic level to the next very inefficient?- Most of it is lost as heat.These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.7. Why would you expect that there will be a greater biomass of plants than herbivores in any ecosystems?- If there were more animals than plants, the animals would not be able to survive. 8. Explain the statement: Energy flow is one-way, but nutrient flow is a cycle.o Energy flow is one-way Energy input from sun  autotrophs  heterotrophso Energy is transformed from one form to another Light energy  heat energy Light energy  chemical energy  heat energy Nutrient flow is a cycle because nutrients can be recycled into the ecosystem.9. What variables in an environment influence the primary productivity in an area?- The amount of sunlight that penetrates the total volume. The ocean has the lowest rate of production because the sunlight only penetrates a small fraction of it Amount of water Amount of sunlight Availability of nutrients Appropriate temperatures.10. What are the differences between ecosystems, communities, and populations?- Ecosystem— All the life living in a particular area together with all the nonliving components of that environment, including water, minerals, and physical factors such as light and air.- Community— Consists of all the populations living in a particular place- Population— Group of individuals of the same species living in the same place at the same time.11. Explain why estuaries and rainforests have high primary productivity, but deserts and oceans have low primary productivity.- They have more plants to absorb the sunlight coming in. with the ocean, there is nothing to absorb the sunlight, thus causing it to have low primary productivity. 12. What are the possible outcomes if two species try to occupy the same niche in the same community?- One will either take over the entire niche, or they will split the niche and not cross into the other’s section13. What factors may affect the carrying capacity of a species in an environment? Is the carrying capacity a fixed number, and why or why not?- The carrying capacity is not a fixed number in an environment. Once the population grows too large, some will die off because they cannot find food to support the large numbers. Then, once many of them die, the population will rise again. It is a rise and fall cycle of population.- Can be increased by new technological advances14. How do you define a biome and what main characteristics classify each biome?- Biome— a major terrestrial or aquatic life zone, characterized by vegetation type in terrestrial biomes and the physical environment in aquatic biomes- Terrestrial— amount of available sunlight is often the most important factor in determining how much life can be sustained in a given area.- Aquatic— Light cannot penetrate deeply into water, so most photosynthesis occurs near the surface.15. What is the relationship between the greenhouse effect and global warming?- The greenhouse effect raises the temperature of the earth, causing global warming16. What is a keystone species and how is it related to biodiversity?- Key stone species— A species whose absence would create significant change in a community.- This species would soon be replaced by another creating a very significant change in the ecosystem they live in.17. What are some biological offenses against invasive species?- Other organisms can attack the invader. For example, Asian rats have become invasive and the mongoose eats them to reduce the