NEET BIOLOGY

Detailed explanation-1: -Answer and Explanation: The correct answer is (b) One species uses another species as food or shelter causing harm.

Detailed explanation-2: -Parasitism is a type of symbiotic relationship. In a parasitic symbiotic relationship one of the partners acts as a parasite and feeds off the other organism. Hence, parasitism is a positive relationship as one organism (parasite) is benefitted from the other.

Detailed explanation-3: -The correct answer is (C) +/+. Mutualism is a type of symbiosis in which both species benefit from the relationship. In a way, the species are mutually benefitting each other. When denoting symbiotic relationships, a “+” symbol indicates that an organism benefits from the relationship.

Detailed explanation-4: -A parasitic relationship is a relationship between two different organisms in which one organism gains at the expense of others without killing it. An example of a parasitism relationship is that of ticks, fleas, lice or leeches on a host such as a human or a dog.