biology review for units 1 2
TRANSCRIPT
Biology Review for Unit 1-2
ECOLOGY AND ECOSYSTEMS
FOOD CHAINSOriginal source of energy for most chains is the sun
1st trophic level is producer
2nd trophic level is primary consumer
2rd trophic level is secondary consumer
Decomposer not shown on chain, but they recycle nutrients
Energy is “lost” as you mover “up” the food chain
SYMBIOSIS
PREDATION– Predator EATS Prey– The populations cycle– Predator has lower curve
– There can’t be more predators than prey
POPULATION GROWTH
EXPONENTIAL GROWTH – LOGISTIC GROWTH
J-curveOccurs when unlimited resources are available
S-curveOccurs because resources are limitedCarrying capacity reached
HUMAN POPULATION GROWTH
Overpopulation of humans leads to
– Destruction of habitats (pollution and/or destroying)
– Loss of biodiversity– Introduced species
–Outcompete nativespecies