Final answer:
In biology, symbiotic relationships can be mutualistic, parasitic, or commensal. Heterotrophism is not a type of symbiotic relationship.
Step-by-step explanation:
In biology, the term 'symbiotic relationship' refers to a close and long-term interaction between two species. The symbiotic relationship can be mutually beneficial, like in mutualism, where both species benefit, or it can be one-sided, like in parasitism, where one species benefits at the expense of the other. Commensalism is another type of symbiotic relationship where one species benefits while the other is neither harmed nor benefited. Heterotrophism, however, is not a type of symbiotic relationship. It refers to organisms that need to consume organic substances for nutrition instead of producing their own nutrients through photosynthesis, like plants and some bacteria do.
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