Food relationships among living organisms

From Online Sciences - October 27, 2017

Food is the main source of energy for all living organisms , where green plants make their own food during photosynthesis process from simple substances which are carbon dioxide gas and water , Sunlight as a source of energy , So , green plants are called producers ( autotrophic organisms ) .

Some animals depend on plants directly , so , these animals are called herbivorous such as rabbit , sheep .etc. , Some other animals depend on plants indirectly , so , these animals are called carnivorous such as lion , snake ..etc. , so, there are many food relationships among living organisms .

Types of food relationships

The types of food relationships are Predation , Symbiosis and Saprophytism .


Predation is a food relationship among living organisms , where one living organism devours another one , Predation occurs between two living organisms , The predator which devours the other living organisms , The prey which is the devoured living organisms .

Predation is a temporary relationship , because it ends by devouring the prey or a part of it , where the predator attacks , kills or devours the prey ,Predation occurs in plant world and animal world .

Predation in plants

Predation is less common in plant world than that in animal world because plants can make their own food ( carbohydrates and protein ) by photosynthesis process , Some plants can not make protein , because they can not absorb some components from the soil .

So , they prey some tiny animals as insects to get their required elements for making protein and these plants are known as insect-eaters ( insectivorous ) plants , such as Drosera and Dionaea , Drosera is an insectivorous plant because it preys some insects to get the required elements for making protein .

Predation in animals

Predation in animals such as a lion preys a deer , a wolf preys a rabbit , a cat preys a rat , Spiders , where they make woven to catch insects , So , Lions , tigers , spiders , wolves , cats , snakes and sharks are considered as predator animals .

Some ways of self-defence against predation in living organisms

Many living organisms have ( appeal to ) different ways of defending themselves against enemies such as camouflage and mimicry .


Camouflage is a phenomenon in which living organisms protects itself ( hides ) from enemies by changing its colour to simulate the colours of its surrounding environment , This phenomenon is found in fish , frogs , birds , chameleon and most insects as butterflies .

Examples of Camouflage


Mimicry is a phenomenon in which the harmless living organisms imitate other harmful or poisonous living organisms to frighten their enemies and escape from them , such as some bees look like wasps in forming lines ( stripes ) on their bodies to frighten their enemies .

Some bees look like wasps in forming lines ( stripes ) on their bodies to frighten their enemies which get afraid of wasps and escape from them .



The benefits of mutualism in human body



External parasitism

Internal Parasitism

Harms of parasitism



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