Unit 1: Ecosystems
What is the difference between a food chain and a food web?
A food chain shows a single energy path; a food web shows interconnected food chains.
What is species richness?
The number of different species in an area.
What is carrying capacity?
The maximum number of individuals an environment can support.
What is the role of the Earth's tilt in seasons?
The tilt causes seasonal variations in sunlight intensity and day length.
What is clear-cutting?
Logging method that removes all trees from an area, impacting biodiversity and erosion.
Define "gross primary productivity."
Gross primary productivity (GPP) is the total amount of solar energy converted into chemical energy by producers.
Define "ecosystem services" and give one example.
Benefits ecosystems provide to humans; example: pollination.
List two density-dependent limiting factors.
Predation, disease, competition.
Name the atmospheric layer that contains the ozone layer.
The stratosphere.
Define "tragedy of the commons."
The overuse of shared resources because individuals act in their own self-interest.
Name one example of a terrestrial biome and describe its climate.
Tropical rainforest — hot, humid, high rainfall year-round.
What is a bottleneck effect in evolution?
A sharp reduction in population size that reduces genetic diversity.
Define Type I, II, and III survivorship curves.
Type I: high survival early, drop late (humans); Type II: constant death rate (birds); Type III: high early mortality (fish).
What is an El Niño event?
A warming of ocean surface waters in the Pacific, disrupting weather patterns.
Compare irrigation methods and their efficiency.
Drip irrigation is most efficient; flood and furrow are less efficient due to runoff and evaporation.
Explain the role of decomposers in nutrient cycling
Decomposers break down organic matter, recycling nutrients into the ecosystem.
Differentiate between generalist and specialist species.
Generalists have broad niches; specialists have narrow niches and specific needs.
Explain the difference between r-selected and K-selected species.
r-selected: reproduce quickly, many offspring; K-selected: fewer, more parental care.
Explain the rain shadow effect.
Moist air rises over mountains, cools, and precipitates; dry air descends on the leeward side.
What are the environmental impacts of urban sprawl?
Loss of habitat, increased runoff, pollution, and traffic congestion.
How does the second law of thermodynamics apply to ecosystems?
Energy is lost as heat when transferred between trophic levels, showing inefficiency.
How does island biogeography theory relate to biodiversity?
Larger, closer islands have more species due to higher immigration and lower extinction rates
Describe the logistic growth model and when it's more accurate than exponential growth.
Logistic growth includes carrying capacity and shows slowing growth as resources become limited.
Describe one anthropogenic cause of soil degradation.
Overgrazing, deforestation, and poor farming practices contribute to erosion and nutrient loss.
How does aquaculture differ from traditional fishing, and what are its pros and cons?
Aquaculture is fish farming; it's more controlled and efficient but may lead to disease, pollution, and escape of non-native species.