OCR A Level Biology: Populations and Sustainability

Limiting factor - Environmental resource or constraint that limits population growth Phases of a population growth curve - Lag, log, stationary Reasons for slight increases and decreases in the stationary phase - Fluctuations in limiting factors Examples of limiting factors - Interspecific competition, disease, temperature, light, pH, availability of water, humidity, predators Types of limiting factor - Biotic, abiotic Examples of biotic factors - Predators, disease, competition Examples of abiotic factors - Temperature, light, pH, availability of water or oxygen, humidity Carrying capacity - Maximum population size that an environment can support Examples of density independent factors - Earthquakes, volcanic eruptions, fires, storms Examples of interactions between populations - Predator-prey, interspecific competition