Ecology basics
What is ecology
THe study of interactions between organisms and their environment
What two major factors determine a biome?
Temperature and Precipitaiton
What organisms make their own food and form the base of most energy pyramids?
Producers or Autotrophes
According to the Rule of 10, approximately what percentage of energy transfers from one trophic level to the next?
What is 10%?
What term describes the maximum population size an environment can sustainably support?
What is carrying capacity?
What is a population?
all members of the same species in a specific place at a specific time.
What is the main difference between weather and climate when studying a biome?
Weather describes short-term atmospheric conditions, while climate describes long-term patterns of temperature and precipitation.
How does a primary consumer differ from a secondary consumer?
A primary consumer eats producers, while a secondary consumer eats primary consumers.
Why is the producer level located at the bottom of an energy pyramid?
Producers capture energy, usually from sunlight, and make it available to the rest of the food web.
How does logistic growth differ from exponential growth?
Exponential growth increases rapidly under ideal conditions, while logistic growth slows as limiting factors cause the population to approach carrying capacity.
A student records sunlight, soil moisture, grass, insects, and birds in a field. Identify one biotic factor and one abiotic factor.
What are grass, insects, or birds (biotic) and sunlight or soil moisture (abiotic)?
A region receives very little precipitation throughout the year. What biome would you predict, and what evidence supports your answer?
What is a desert or tundra? Its low precipitation is the key evidence.
In a food chain of grass → grasshopper → frog → snake, what trophic level does the frog occupy?
What is the secondary consumer level?
Producers contain 5,000 units of energy. Using the Rule of 10, how much energy would be available to primary consumers?
What are 500 units of energy?
A population of deer increases rapidly when food is plentiful and predators are scarce. What type of population growth might initially describe this pattern?
What is exponential growth?
Two locations have the same weather today, but one has much colder average winters over many years. Which ecological factor differs between the locations?
climate
Two locations have similar precipitation, however, one has changes in temperature throughout the year, and one is a steady temperature all year round, where might these be located?
One is temperate and one is tropical
In a food web, the rabbit population decreases sharply. Predict one possible effect on a predator that depends heavily on rabbits for food.
The predator population may decrease because less food is available, or the predators may switch to other prey and increase pressure on those populations.
A food chain has producers with 10,000 units of energy. Approximately how much energy reaches the tertiary consumers under the Rule of 10?
What are 10 units of energy? Primary consumers receive 1,000, secondary consumers receive 100, and tertiary consumers receive 10.
A disease spreads more easily as a population becomes crowded. Is this a density-dependent or density-independent limiting factor? Explain why.
What is a density-dependent limiting factor? Its effect increases with population density because crowded organisms are more likely to spread the disease.
A forest contains many populations of plants, animals, fungi, and bacteria interacting with one another and with soil, water, and sunlight. Explain why this is an ecosystem rather than just a community.
An ecosystem includes both living organisms and nonliving environmental factors, while a community includes only interacting populations of living organisms.
A climate diagram shows consistently warm temperatures and high precipitation throughout the year. Predict the most likely biome and explain how both climate patterns support your prediction.
What is a tropical rainforest? Warm temperatures and abundant precipitation support dense vegetation and high productivity throughout the year.
A pesticide kills most of the decomposer bacteria in an ecosystem. Explain how this could affect nutrient availability and producers over time.
Decomposition would slow, reducing the recycling of nutrients into the soil. Producers could have fewer available nutrients, reducing plant growth and affecting the rest of the food web.
An ecosystem loses most of its producers because of a severe drought. Explain why this could eventually affect organisms at every trophic level, even if those organisms are not directly affected by the drought.
Producers supply the energy that enters most food webs. With fewer producers, less energy is available to primary consumers and subsequently to higher-level consumers, potentially causing population declines throughout the ecosystem.
A deer population exceeds its carrying capacity after several years of abundant food. Food becomes scarce, and deaths increase. Predict what may happen to the population and explain why.
The population may decline toward carrying capacity because limited food increases competition and mortality. The population could fluctuate as resource availability changes.