Biotic and Abiotic Factors

https://www.revisely.com/gcse/biology/aqa/video/IvF

What are the 4 main biotic factor

The availability of food, if availability of food falls, then number of organisms in the community will also win.

The arrival of a new predator, this can cause population of a prey species to fall, can also affect existing preds e,g if they compete for same prey

Competition between species, if species is out competed, then its population can fall so much, that numbers are no longer sufficient to breed, and species becomes extinct.

New pathogens, if an infectious disease emerges and spreads, it can wipe out whole population of species,

What are the seven abiotic factors.

Light intensity, effect on plants photosynthesis. If plants grow slow, then animals feeding on plants may not have enough food

Temperature, change in temp could cause distribution of species to change, e.g animals might migrate and plant species might disappear from that area.

Water

pH and mineral content of soil, many cant grow on soil too acidic . alkaline.

Wind intensity affects plants,

Carbon dioxide and oxygen, needed for photosynthesis. Oxygen needed for aerobic respiration, level of dissolved oxygen in water can fall on hot days, can be harmful to aquatic organisms.

a

a

a

a