The type of nutrition exhibited when organism lives on the body surface or inside the body of another type of organism is

Step 1: Analyze the question The question asks for the type of nutrition in which an organism lives on the surface of, or inside, another organism (the host).

Step 2: Explain the concept Modes of nutrition include:

• Holozoic: the organism ingests solid food and digests it internally (e.g. humans, dogs, lions).
• Parasitic: the organism lives on (ectoparasite) or in (endoparasite) another living organism, called the host, and obtains food from it, usually harming the host (e.g. tapeworm, lice, Plasmodium).
• Saprophytic: the organism feeds on dead or decaying organic matter (e.g. mushrooms, bread mould).
• Carnivores: not a mode of nutrition but a category of animals that eat flesh. It is a type of holozoic feeding, and it is also in the wrong form for this question.

Step 3: Solve

• A. Holozoic: feeds by ingestion, with no requirement of living on another organism. ✘
• B. Parasitic: lives on or inside a host and feeds from it. ✔
• C. Saprophytic: feeds on dead matter, not living hosts. ✘
• D. Carnivores: animals that eat other animals, not a nutrition type tied to living on a host. ✘

Step 4: Answer The correct option is B. Parasitic.

Tip: Link "parasite" with "living beside/on a host". Parasites live on or in a living host, while saprophytes feed on dead matter. Ask yourself "Is the food source alive and is the organism living on or in it?" If yes, it is parasitic.