The type of nutrition shown by spirogyra is

Step 1: Analyze the question The question asks how Spirogyra obtains its food. Spirogyra is a filamentous green alga found in ponds and slow-moving freshwater, and it is easy to recognize by its spiral, ribbon-like chloroplasts.

Step 2: Explain the concept Here are the types of nutrition in the options:

• Symbiosis: two organisms live together and both benefit, e.g. lichens (alga and fungus).
• Holozoic: ingestion of solid food, digestion inside the body, then absorption. This is typical of animals like humans, dogs and Amoeba.
• Chemosynthetic: energy comes from oxidizing inorganic chemicals instead of light, e.g. nitrifying bacteria such as Nitrosomonas.
• Holophytic: the organism makes its own food by photosynthesis, using chlorophyll, sunlight, carbon dioxide and water. This is typical of green plants and algae.

Step 3: Solve

• Spirogyra contains chlorophyll in its spiral chloroplasts.
• It uses sunlight, CO₂ and water to make carbohydrates (starch is stored in structures called pyrenoids).
• It does not ingest food, so it is not holozoic.
• It does not depend on a partner organism, so it is not symbiotic.
• It uses light, not chemical oxidation, so it is not chemosynthetic.

Spirogyra is therefore an autotroph that feeds by photosynthesis, which is holophytic nutrition.

Step 4: Answer The correct option is D. Holophytic.

Exam tip: Link the prefix to the meaning. Holo-zoic means "whole animal" (eating like an animal), while Holo-phytic means "whole plant" (feeding like a plant, by photosynthesis). If an organism is green and has chlorophyll, think holophytic.