IB ESS Ecosystems and Ecology (shortened)

Organism

Organism

An individual animal, bacteria, or plant that is alive.

Population

A group of organisms of the same species living together.

Species

Organisms of the same type with common characteristics that can interbreed to create fertile offspring.

Community

A group of populations of different species living in the same area.

Ecosystem

Community plus abiotic factors like rocks, water, and sunlight.

Biome

Type of environment with specific traits like tundra or grasslands.

Biosphere

All ecosystems on Earth.

Chain

Single line of organisms connected by arrows showing energy flow.

Web

Multiple chains showing energy transfer in an ecosystem.

Arrow

Indicates what eats what and how energy is transferred.

Trophic level

Tier in a pyramid/chain indicating an organism's position in the food chain.

Ecological Pyramids

Show energy/biomass flow in an ecosystem.

1st Law of Thermodynamics

Energy can't be created or destroyed, only transformed.

2nd Law of Thermodynamics

Energy transfer is inefficient, with some loss.

Producer

First trophic level, produces energy through photosynthesis.

Primary consumer

Eats producers, second trophic level.

Secondary consumer

Eats primary consumers, third trophic level.

Tertiary consumer

Eats secondary consumers, fourth trophic level.

Apex predator

Top predator at the fifth trophic level.

10% rule

Only about 10% of energy transfers between trophic levels.

Pyramid of numbers

Shows the abundance of species in an ecosystem.

Pyramid of biomass

Illustrates the mass of living organisms in an area.

Pyramid of energy

Depicts the flow of energy in an ecosystem.

Bioaccumulation

Toxins building up in an organism at a trophic level.

Biomagnification

Toxins increasing in strength across trophic levels.

Productivity

Amount of biomass/energy transferred between trophic levels.

Gross primary productivity

Rate at which producers photosynthesize.

Net primary productivity

GPP minus respiration, the stored energy.

Secondary productivity

Biomass added to consumers per time period.

Bottle Method

Technique to measure GPP and respiration in organisms.