<span>Altruism is a selfless behavior so the animal would behave that way because it's intention is to put others before itself.
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They are considered so because are the indispensable parts of the nature cycle.Without formation,decay cannot be possible and similarly,formation cannot be possible without decay.In addition to this,THEY ARE IN A CHRONOLOGICAL MANNER SET BY NATURE and that's why cannot be seperated and so together constitute the cycle of nature.
It is essential because without it plants would have no source of energy. Therefore disrupting the whole food chain.
Answer:haemoglobin
Explanation:
Inside the air sacs, oxygen moves across paper-thin walls to tiny blood vessels called capillaries and into your blood. A protein called haemoglobin in the red blood cells then carries the oxygen around your body.
