biosphere

ecosystem

Biotic

abiotic

producer

primary consumer

secondary consumer

tertiary consumer

trophic level

pyramid of numbers

pyramids of biomass

species

population

community

habitat

niche

mutualism

Parasitism

dichotomous keys

Biome

photosynthesis

respiration

Gross productivity

net productivity

primary productivity

secondary productivity

limiting factor

carrying capacity

Density dependant factors

density-independant factors

K - strategists

r - strategists

succession

sere

Zonation