Ecosystems
What is the primary source of energy for most ecosystems?
The sun.
What are producers and why are they important in an ecosystem?
Producers are organisms that make their own food, usually through photosynthesis. They are fundamental to providing energy for the ecosystem.
What is the First Law of Thermodynamics in relation to ecosystems?
Energy cannot be created or destroyed, only transformed.
What is a food chain?
A food chain is a linear sequence that shows how energy and nutrients flow between organisms, starting with producers.
What is a food web?
A food web is a complex network of interconnected food chains showing how energy and nutrients flow through an ecosystem.
Which ecosystem is known for having the highest terrestrial productivity?
Tropical rainforests.
What percentage of energy is typically transferred from one trophic level to the next?
Approximately 10%.
Describe the process of photosynthesis in one sentence.
Photosynthesis is the process by which plants convert sunlight, carbon dioxide, and water into glucose and oxygen.
What role do decomposers play in a food chain?
Decomposers break down dead organisms and recycle nutrients back into the ecosystem.
How does a food web demonstrate ecosystem stability?
A food web shows multiple food sources for organisms, which can maintain ecosystem balance and resilience against disruptions.
What term describes the various living organisms in an ecosystem?
Biotic factors.
Define primary consumers and give an example.
Primary consumers are herbivores that eat producers.
Example: rabbits.
What happens to most energy as it is transferred through trophic levels?
Most energy is lost as heat during transfer.
Give an example of a simple food chain.
Sample Example: Grass → Rabbit → Fox.
What happens when one species in a food web is removed?
What happens when one species in a food web is removed?
Answer: The removal can disrupt the balance, leading to population changes and possibly affecting many other species.
What is the difference between an ecosystem and a biome?
An ecosystem is a community of living organisms and their interactions with abiotic factors, while a biome encompasses multiple ecosystems that share similar climate and geography.
What are tertiary consumers?
Tertiary consumers are top predators that eat secondary consumers. They receive the least amount of energy in the food chain.
Define Gross Primary Productivity (GPP).
GPP is the total amount of energy captured by plants through photosynthesis.
How does energy flow in a food chain?
Energy flows in one direction, from producers to primary consumers and then to higher trophic levels.
Why is biodiversity important in a food web?
Biodiversity increases ecosystem resilience, allowing it to recover from changes and maintain stability.
Name an ecosystem with the lowest productivity and explain why it is less productive.
Deserts; they receive very little precipitation and have limited resources.
Explain the concept of the energy pyramid.
The energy pyramid illustrates the decrease in energy available at each trophic level, showing that energy diminishes as you move up the pyramid.
What is Net Primary Productivity (NPP) and how is it calculated?
NPP is the energy available to consumers after plant respiration, calculated as NPP = GPP - Respiration.
What is the significance of the 10% rule in food chains?
The 10% rule indicates that only 10% of the energy from one trophic level is available to the next level, highlighting energy loss at each step.
Explain the impact of invasive species on food webs.
Invasive species can outcompete native species, disrupt food webs, and lead to decreases in biodiversity and ecosystem health.