Which of the following modes of nutrition Is autotrophic?

Step 1: Analyze the question The question asks which mode of nutrition is autotrophic. Autotrophic organisms make their own food from simple inorganic substances.

Step 2: Key concept

• Autotrophic nutrition: the organism manufactures its own food, usually by photosynthesis (using light) or chemosynthesis (using chemical energy).
• Heterotrophic nutrition: the organism depends on other organisms for ready-made food.

Step 3: Examine each option

• A. Holophytic: "Holo" means whole and "phytic" means plant-like. Holophytic nutrition is the plant-like way of feeding, in which green plants make food from CO₂ and water using sunlight and chlorophyll. This is autotrophic.
• B. Holozoic: the organism ingests solid food and digests it internally, as in humans, dogs, and goats. This is heterotrophic.
• C. Parasitic: the organism feeds on a living host and harms it, as with tapeworms and mistletoe. This is heterotrophic.
• D. Saprophytic: the organism feeds on dead, decaying organic matter, as with mushrooms and bread mould. This is heterotrophic.
• E. Symbiotic: two organisms live together for mutual benefit, as with nitrogen-fixing bacteria in legume root nodules. This is a relationship, not an autotrophic mode of nutrition.

Step 4: Answer The only autotrophic mode of nutrition listed is holophytic, which is option A.

Tip: Remember "Holo-PHYTE = PLANT", so holophytic means feeding like a plant. Also, "Holo-ZOO = ANIMAL", so holozoic means feeding like an animal. For autotroph questions, look for the option linked to plants or photosynthesis.