Bio G Biotic And Abiotic Flashcards
(12 cards)
Biotic factors
Living parts of the environment
Abiotic factors
Non living parts of the enviorment
Biotic factor - food
All animals eat other living organisms. All sources of food are biotic. If food falls then the number of organisms in that community also falls
Biotic factor - arrival of a new predator
This can cause the population of a prey species to fall. Can also affect existing predators - competing for the same prey.
Biotic factor - competition between species
If a species is outcompeted then its population can fall so much that numbers are no longer sufficient to breed and the species may become extinct
Biotic factor - new pathogens
If an infectious disease emerges then spreads, it can wipe out a population of a species
Abiotic factor - light intensity
Effect plant - photosynthesis. Too low then rate of photosynthesis falls and plants will grow more slowly. Effect whole community - if plant grow to slowly then animals which feed on plants may not have enough food
Abiotic factor - temp
If temp changes then this can cause distribution of species to change. Eg animals can migrate
Abiotic factor - water
Both animals and plants need it to survive. Many are adapted to survive with low levels of
Abiotic factor - PH and mineral content of soil
Many plants cannot grown on soil which are too acidic or too alkaline. Plants also need certain minerals eg nitrate - amino acids and proteins
Abiotic factor - wind intensity and direction
Strong winds blowing in land from sea can cause plants to lose water. Plants growing in sand dunes are often adapted to reduce water loss
Carbon dioxide and oxygen
CO2 needed for plants to photosynthesis and if CO2 levels fall then the rate of photosynthesis also decrease. Oxygen is needed for aerobic respiration. Dissolved oxygen in water can fall - harmful for fish
