Q.Describe different modes of nutrition in angiosperms.

Besides normal photosynthesis, angiosperms show parasitic, saprophytic, insectivorous, and symbiotic modes of nutrition.

1. Autotrophic (holophytic) nutrition: the vast majority of green angiosperms synthesise their own food by photosynthesis, using chlorophyll, CO2, water and sunlight.
2. Heterotrophic modes (found in non-green or partially non-green angiosperms that cannot meet all nutritional needs by photosynthesis alone): a. Parasitic nutrition -- obtaining nourishment from a living host via specialised absorptive organs called haustoria.
   • Total (holo)parasites -- completely lack chlorophyll and are wholly dependent on the host, e.g. Cuscuta (dodder, a stem parasite lacking roots and leaves) and Rafflesia.
   • Partial (hemi)parasites -- possess chlorophyll and photosynthesise, but draw water and minerals from the host, e.g. Viscum album and Loranthus (both stem hemiparasites, 'mistletoes'). b. Saprophytic nutrition -- obtaining nourishment from dead and decaying organic matter, usually via an associated mycorrhizal fungus, since the plant itself lacks chlorophyll, e.g. Monotropa, Neottia. …