Unit 1 - Energy and Matter Flow

Unit 1 - Energy and Matter Flow

• Energy in most ecosystems originates from the sun.
• Abiotic factors are non-living elements (e.g. air, water, rocks).
• Biotic factors are living elements (e.g. plants, animals, fungi).
• Organism: single living thing
• Population: all organisms of one species in a specific area
• Community: all living things in an ecosystem
• Ecosystem: biotic and abiotic factors in an area
• Biome: all members of the same species in an area
• Biosphere: all parts of Earth capable of supporting life
• Autotrophs produce their own food from sunlight (e.g., plants).
• Heterotrophs obtain energy by consuming other organisms (e.g., animals).
• Food chains display energy flow; arrows show the direction.
• Food webs depict the complex interrelationships in an ecosystem.
• Only 10% of energy transfers between trophic levels.

Levels of Ecology

• Organism: a single, individual living thing.
• Population: a group of the same species living in the same area.
• Community: all populations in an area that interact with each other.
• Ecosystem: all biotic (living) and abiotic (non-living) factors in a given area.
• Biome: a large geographic area characterized by similar climate and dominant plant life.
• Biosphere: The sum of all ecosystems on Earth.

Differences between Autotrophs and Heterotrophs

• Autotrophs (producers) make their own food (e.g. plants).
• Heterotrophs (consumers) obtain energy by consuming other organisms.

Food Chains and Food Webs

• Food chains show the linear flow of energy from one organism to another.
• Food webs show the complex network of interactions among organisms in an ecosystem.
• Arrows in a food chain indicate the direction of energy transfer.

Energy Transfer

• Energy flows through an ecosystem in one direction.
• Only a portion (10%) of energy is transferred from one trophic level to the next.
• The remaining energy is released into the atmosphere as heat.

Unit 2 - Biomes and Adaptations

• Biomes are large geographic areas with similar climates and plant life.
• Different biomes support various animal and plant species.

Unit 3: Biodiversity

• Symbiosis is a close relationship between two or more different species.
  • Mutualism: (+/+) both benefit.
  • Commensalism: (+/0) one benefits, the other is unaffected.
  • Parasitism: (+/-) one benefits, the other is harmed.
• Invasive species can disrupt ecosystems, often negatively impacting biodiversity.

Unit 4 - Populations

• Population density is the number of individuals per unit area.
• Limiting factors affect population growth (e.g., food, water, predators).
• Exponential growth occurs when a population increases rapidly.
• Logistic growth occurs when a population's growth slows as it reaches carrying capacity.
• Carrying capacity is the maximum population size an environment can sustain.
• Density-dependent factors affect a population based on its density (e.g., competition, disease).
• Density-independent factors affect a population regardless of its density (e.g., natural disasters).