Ecology interactions among organisms part 2 - 30th and 31st July

Abiotic Factors

Light 

– Affects many living organisms, not just plants
 

Temperature

– Affects physiological activities of all living organisms
 

Water

– Essential for life
– Organisms may have specially adapted features for survival in places with a lot of or very little water

Oxygen

– Most organisms are aerobes
 

Salinity

–Important factor for aquatic organisms
– Also a factor for other organisms
 

pH (Note! Must be small letter 'p' and capital letter 'H'. )

–May be influenced by photosynthetic activity of aquatic plants

Some Chemistry...

pH level is the measure of acidity of a certain substance. 

Acid (pH 1.0 - 6.9)

Alkaline (pH 7.1 - 14.0) 

Neutral - not acid or alkaline (water) 

Biotic Factors 

1. Symbiosis a long-term relationship between two different species “living together”. The relationship varies in population, can be mutualism, commensalism & parasitism.

Mutualism

Each population benefits. The interaction is necessary for the survival and growth of each species
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Commensalism

One population benefits; the other is unaffected 

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Parasitism

One population benefits (parasite) while the other is harmed (host). The interaction is necessary for the survival of the parasite.
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2. Competition - Both population compete with each other for limited resources in the same ecosystem; both species are adversely affected by the relationship.
Interspecific (a form of symbiosis) or intraspecific (same species) competition
-/-

3. Predation - One population feeds on the other. The interaction is necessary for the survival of the predator

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