Which term is defined as a type of relationship where one organism benefits and the other is harmed?

Which term is defined as a type of relationship where one organism benefits and the other is harmed?

• A. Parasitism
• B. Mutualism
• C. Commensalism
• D. Symbiosis

Answer: (A)

Parasitism is a relationship in which one organism benefits at the expense of another. The parasite gains nutrients, shelter, or a habitat, while the host suffers harm, such as reduced fitness or health problems. This fits the described concept because the benefit goes to one participant and the cost to the other. For contrast, mutualism involves both organisms benefiting; commensalism is when one benefits while the other is largely unaffected; and symbiosis is a broader term that covers several types of close associations, not a single one-sided harm. Examples include tapeworms in the intestines or ticks feeding on blood, illustrating the one-sided advantage that defines parasitism.

Parasitism is a relationship in which one organism benefits at the expense of another. The parasite gains nutrients, shelter, or a habitat, while the host suffers harm, such as reduced fitness or health problems. This fits the described concept because the benefit goes to one participant and the cost to the other. For contrast, mutualism involves both organisms benefiting; commensalism is when one benefits while the other is largely unaffected; and symbiosis is a broader term that covers several types of close associations, not a single one-sided harm. Examples include tapeworms in the intestines or ticks feeding on blood, illustrating the one-sided advantage that defines parasitism.